1. SOME BASIC CONCEPTS OF CHEMISTRY 1. State State Law Law of Multip Multiple le propor proportio tion. Who proposed this law?
It states states that when when two eleme element nt s combine combine to form form more more than one com!ou com!ound, nd, the different masses of one of the elements that combine with a fixed mass of the other, is in a sim!le whole number r atio. This law was !ro!osed b o!n Dalton. 2. State Law of Definite (Constant proportion. Who proposed this law?
It states that a given compound always contains exactly the same proportion of lements by weight. Or, the same compo ompoun und d alwa always ys conta ontain inss the the same elements combined in a fixed ratio by mass . This law was !ro!osed b ose"!
Proust. 3. Stat State e Law Law of cons conser erva vati tion on of ss (atter). Who proposed this law? create ted d nor nor dest destro royed yed.. Or, Or, in a che chemi mica call rea reacction, the total mass of reactants is It states that matter can neither be crea equal to the total mass of produ cts. This law was !ro!osed b Antoine Lavoisier .
!. Define a..u th
12
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1/12 the mass of a C atom is called atomic mass unit (amu). ". Define olar ass
The ma mass of one mole of of a substance in "ram is called its molar mass. #. Define 1 ole.
12
1 mole mole is is the the amou amount nt of of subs substa tan nce that that cont contai ains ns as man many y par parti ticl cles es as ther there e are are atoms in exactly 12 g C isotope. 1 23
ole of an$ su%stance contains #.&22 ' 1& atos. This number is nown as - oadro nu%er or -voadro
(NA or N). constant (N . Define ass percentae.
It is the !ercenta"e of each ele ents !resent in 1" of a substance.
i.e. i.e. !ercen !ercenta" ta"e e com!o com!osit sition ion (ma (mass !ercent) !ercent) of an an elemen elementt % $ass $ass of of that that eleme eleme t in the com!ound x 1 $olar mass of he com!ound
#r, #r, $ass $ass !er !ercen cent % $as $ass of solute & 1 $ass of solution *. What What are are ep epir iric ical al and and ol olec ecu ular forulae?
'm!irica 'm!iricall formula formula is the sim!les sim!lest formula which "ies onl the ratio of different lements !resent in the com!ound. *ut *ut mol molec ecul ular ar form formul ula a is is the the act act ual ual form formul ula a tha thatt "i "ies es the the exa exact ct numb number er of diff diffe e ent elements !resent in the sam!le. +. ,ind the nu%er of oles and
olecules present in +& water.
No. of moles(n) % +ien mass in "ram (w) % /10 % moles $olar ma s ($) 2
No. of molecules % no. of moles x .22x 1 % x .22x 1
2
1&. What is liitin reaent?
The The rea rea"e "ent nt wh which ich limi limits ts a rea react ction or the rea"ent rea"ent which which is com!letel com!letel consume consume in a chemical reaction is called limitin" rea"ent or limitin" react ant. 11. Define olarit$ and olalit$.
$olari $olarit t is is defin defined ed as as the the numb number of moles of solute dissoled !er litre of soluti n. i.e. .e. $o $olar larit it ($) ($) % Nu Numb mber er of m oles of solute (n) -olume of s lution in litre (-) $olali $olalit t is def define ined d as the num numb b r of moles of the the solute solute !resent !resent !er !er ilo"r ilo"ram am ( ) of the solent. Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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i.e. $olalit (m) % Number of moles of solute $ass of solent in " 12. ,ind the olarit$ of a solution repared %$ dissolvin ! of 4a56 dissolves in "& L solution.
$olarit $olarit ($) ($) % Number Number of mole mole of solute (n) -olume of solution in litre (-) No. of moles moles of Na#3 % +ien ass/ $olar mass % 4/4 % .1 mol -olu -olum me of of so soluti lution on in 5 % 2/ 2/1 1 % .2 5 $olarit % .1/.2 % .4$
%. STR&CT&RE OF ATOM 1. ,ind the nu%er of protons electrons and neutrons in the followin. 3" 3" 3# 1 Cl 1 Cl/ 1 Cl/ Ans6 No. of 7rotons 8 electrons % Atomic number No.. of No of ele elect ctro rons ns in an ion ion % Ato ic number 9 char"e of the ion (for ( for ?e ions) or, tomic number ? char"e on the ion (for 9e ions) No. of neutrons % $ass number ? Atomic number :!ecies No. of 7rotons No. f electrons No. of neutrons 1; 1; <1; % 10 1; Cl 1; 10 <1; % 10 1; Cl< 1; 10 <1; % 1 1; Cl< 2. 0ive the scatterin e'perient cond onduct ucted ed %$ uthe utherf rford ord.. What What are the the iport iporta a t o%servations and conclusions ade %$ utherford? =utherford !ro!osed an atom model based on his >?!article scatterin" x!eriment. 3e bombarded a er thin thin "old "old foil foil with with >?!ar >?!artic ticles les.. T e "old "old foil foil had had a circular circular fluoresc fluorescent ent @inc sul!hi sul!hi e screen around it. O#servations6 i. $ost of the >? !articles !assed throu"h the "old foil without an deiati on. ii. A small fraction of the ?!articles was deflected b small an"les. iii. A er few >? !articles ( ∼1 in 2, 2,) ) boun bounce ced d bac, bac, that that is, is, were were defle deflecc ted b nearl 10D. rom m the the abo aboe obs obser era attions, =utherford made the followin" conclusions6 Con$lusions6 ro i. :inc ince mos mostt of the the >?!ar ?!artticle icless !a !a ssed throu throu"h "h the the foil without without an an deiatio deiation, n, mo t s!ace in the atom is em!t. ii. A few !ositi itiel ch char"ed >? !ar icles were were deflected. deflected. This is because the the !ositi char"e of the atom is i s concentrated in a er er sm small all o olum lume at at the ce ce tre called nucleus. iii. The o olume oc occu!ied b th the nu nu leus is ne"li"ibl small as com!ared to the total olume of the atom. 3. What are the postulates of uth rford ato odel? =utherford !ro!osed the Accor ordi din" n" to this model6 the nuc nucle lea ar odel (lanetar$ odel) of ato. Acc i. All All the the !osi !osittie ie cha char" r"e e and mo most st of the the ma mass ss of the the ato atom m wer were e con conccentr entr ted in the centre called nucleus. ii. 'lectrons are reolin" r ound ound the the nucl nucleus eus with with a er er hi"h hi"h s!e s!eed ed in circu circular !aths called orbits. iii. 'lec 'lectr tron onss and and the the nuc nucle le s are held to"ether b electrostatic forces of att raction. !. What are the draw%acs of utherford ato odel? i. 3e could could not not ex! ex!lai lain n th stabilit of the atom. ii. 3e could could not not ex! ex!lai lain n th electronic structure of atom. ". What What is ph phot otoe oele lect ctri ricc eff effec ect? t? W at are its characteristics? It is is the !henomeno !henomenon n of eBect eBectio io of electrons b certain metals (lie !otassium, ubidium, caesium etc.) when li"ht of suitab suitable le freue freuenc nc incident incident o them. The electrons eBected are called !hotoel ectrons. The im!ortant characteristics of !hot electric effect are6 i. The The elec electro trons ns are eBect eBected ed from from t he meta metall sur surfa face ce as soon soon as the the bea beam m of of li" li"ht ht st ies the surface. ii. The numbe numberr of electr electrons ons eBect eBecte e is !ro!ortional to the intensit or bri"htness of li"ht.
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Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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i.e. $olalit (m) % Number of moles of solute $ass of solent in " 12. ,ind the olarit$ of a solution repared %$ dissolvin ! of 4a56 dissolves in "& L solution.
$olarit $olarit ($) ($) % Number Number of mole mole of solute (n) -olume of solution in litre (-) No. of moles moles of Na#3 % +ien ass/ $olar mass % 4/4 % .1 mol -olu -olum me of of so soluti lution on in 5 % 2/ 2/1 1 % .2 5 $olarit % .1/.2 % .4$
%. STR&CT&RE OF ATOM 1. ,ind the nu%er of protons electrons and neutrons in the followin. 3" 3" 3# 1 Cl 1 Cl/ 1 Cl/ Ans6 No. of 7rotons 8 electrons % Atomic number No.. of No of ele elect ctro rons ns in an ion ion % Ato ic number 9 char"e of the ion (for ( for ?e ions) or, tomic number ? char"e on the ion (for 9e ions) No. of neutrons % $ass number ? Atomic number :!ecies No. of 7rotons No. f electrons No. of neutrons 1; 1; <1; % 10 1; Cl 1; 10 <1; % 10 1; Cl< 1; 10 <1; % 1 1; Cl< 2. 0ive the scatterin e'perient cond onduct ucted ed %$ uthe utherf rford ord.. What What are the the iport iporta a t o%servations and conclusions ade %$ utherford? =utherford !ro!osed an atom model based on his >?!article scatterin" x!eriment. 3e bombarded a er thin thin "old "old foil foil with with >?!ar >?!artic ticles les.. T e "old "old foil foil had had a circular circular fluoresc fluorescent ent @inc sul!hi sul!hi e screen around it. O#servations6 i. $ost of the >? !articles !assed throu"h the "old foil without an deiati on. ii. A small fraction of the ?!articles was deflected b small an"les. iii. A er few >? !articles ( ∼1 in 2, 2,) ) boun bounce ced d bac, bac, that that is, is, were were defle deflecc ted b nearl 10D. rom m the the abo aboe obs obser era attions, =utherford made the followin" conclusions6 Con$lusions6 ro i. :inc ince mos mostt of the the >?!ar ?!artticle icless !a !a ssed throu throu"h "h the the foil without without an an deiatio deiation, n, mo t s!ace in the atom is em!t. ii. A few !ositi itiel ch char"ed >? !ar icles were were deflected. deflected. This is because the the !ositi char"e of the atom is i s concentrated in a er er sm small all o olum lume at at the ce ce tre called nucleus. iii. The o olume oc occu!ied b th the nu nu leus is ne"li"ibl small as com!ared to the total olume of the atom. 3. What are the postulates of uth rford ato odel? =utherford !ro!osed the Accor ordi din" n" to this model6 the nuc nucle lea ar odel (lanetar$ odel) of ato. Acc i. All All the the !osi !osittie ie cha char" r"e e and mo most st of the the ma mass ss of the the ato atom m wer were e con conccentr entr ted in the centre called nucleus. ii. 'lectrons are reolin" r ound ound the the nucl nucleus eus with with a er er hi"h hi"h s!e s!eed ed in circu circular !aths called orbits. iii. 'lec 'lectr tron onss and and the the nuc nucle le s are held to"ether b electrostatic forces of att raction. !. What are the draw%acs of utherford ato odel? i. 3e could could not not ex! ex!lai lain n th stabilit of the atom. ii. 3e could could not not ex! ex!lai lain n th electronic structure of atom. ". What What is ph phot otoe oele lect ctri ricc eff effec ect? t? W at are its characteristics? It is is the !henomeno !henomenon n of eBect eBectio io of electrons b certain metals (lie !otassium, ubidium, caesium etc.) when li"ht of suitab suitable le freue freuenc nc incident incident o them. The electrons eBected are called !hotoel ectrons. The im!ortant characteristics of !hot electric effect are6 i. The The elec electro trons ns are eBect eBected ed from from t he meta metall sur surfa face ce as soon soon as the the bea beam m of of li" li"ht ht st ies the surface. ii. The numbe numberr of electr electrons ons eBect eBecte e is !ro!ortional to the intensit or bri"htness of li"ht.
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Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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iii. or or eac each h met metal al,, the therre is is a min minim imum freuenc (nown as threshold freuenc EF O) below which !hotoelectric effect is not obsered. i. The inet inetic ic ener" ener" of of the eBecte eBecte elect electron ronss is direct directl l !ro!or !ro!ortio tional nal to the freue freue c of the incident li"ht. #. 0ive the differ different ent lines lines present present i the line spectru of h$droen ato. The hdro"en s!ectrum consists of mailnl fie series of lines which are *+an Bal+er Pas$!en Bra$-ett an' P(un' series. Amon" these lines, the *almer series is the onl series that we can be isible. Series S"e$tral re)ion L*+an <ra violet Bal+er ,isi#le Pas$!en In(ra re' Bra$-ett In(ra re' P(un' In(ra re' . 0ive the iport iportant ant postulates postulates o 7ohr -to odel. i. The The ele elect ctro ron n in the the hd hdro ro" " n atom atom can moe around around the the nucleus nucleus in in a circu circull ar !ath of fixed radius and ener". These These !at !aths hs are are calle called d orbi orbits or stationar states or allowed ener" states. ii. The ener" ener" of an elect electron ron i n the orbit does not chan"e with time. iii. The freuenc of radiation abso absorb rbed ed or emit emitte ted d whe when n tra trans nsit itio ion n occ occur urss bet bet een two stationar states that dif differ fer in ener ner" b b G', G', is "i "i en b6 F % G' % '2 ? '1 h h i. The an"ular momentum of an electron is an inte"ral multi!le of h/2H. *. What are the liitations of 7ohr ato odel? i. It could could not not ex!lai ex!lain n the fin s!ectrum of hdro"en atom. ii. It could not ex!lain the s!e ctrum of atoms other than hdro"en. iii. It was unable to ex!lain St r- e((e$t and /ee+an e((e$t. i. It coul could d not not ex!l ex!lai ain n the the abil abilit of atoms to form molecules b chemical bon s. +. What do $ou ean %$ the dual ature of atter? $atter has two t!es of nature !article nature and wae nature. This is nown as the dual nature of matter. 1&. 0ive the de 7rolies 7rolies e8uation e8uation an and e'plain the ters? An euati euation on relat relatin" in" wael waelen"t en"t () and momentum (!) of a material !article is nown as de *ro"lies euation. The euation is6 % h/m Jhere m is he mass of the !article, is the elocit and ! is the momentum. 11. State 6eisen%er9s uncertaint$ principle. 0ive its atheatical for. sible e to to det deter ermi mine ne simu simulta ltane neou ously sly,, the the exac exactt pos position and exact momentum (or It states that K it is impossibl velocity velocity of a moving microscopi microscopic particle li!e electron" . $athematicall, $athematicall, it can be "ien as in euation6 Gx. G! L h 4H Jhere Gx is the uncertaint in ! osi osition ion and and G! (or (or, G) G) is the unce uncerrtain aint in mo mom m entum (or elocit) of the !article. 12. What are :uantu nu%ers? ; plain the different 8uantu nu%ers. These These are certa certain in number numbers used to ex!lain the si@e, sha!e and orientation of orbitals. #r, Muantum numbers are the address of an electron. here are four uantum numbers which describe the electron in an atom. The are 7rinci!al Muantum number (n), @imut @imuthal hal Muantu Muantum m num number ber (), (), $a"ne $a"netic tic Muant Muantum number (m or m ) and :!in Muantum number (s) 1. rincipal :uantu 4u%er (n) The The fo follo llowin" in" inf informa ormatti ns are obtained from n. 1. It "ies the si@e the orbit. 2. It "ies the ener" of electron in an orbit.
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Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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3. It "ies the shell in which the el ctron is found. 4. It also "ies the aera"e distanc between the electron and the nucleus. The !ossible alues of n are 1, 2, , 4, etc. If n % 1 the electron is in P shell n % 2 the electron is in 5 shell n % the electron is in $ shell and so on. 2. -
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!. Spin :uantu 4u%er (s or s ) It is the onl ex!erimental Muantum number and it "ies the s!in of electrons. he alues for s ma be 9R or
1!. Which are the different t$pes of d>or%itals? Draw their shapes. 2 2 2 There are t!es of d
1". Which are the different rules for fillin electrons in or%itals? State the.
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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The fillin" of electrons into t he orbitals of different atoms taes !lace accord in" to the rules < aufbau !rinci!le, 7auliSs exclusion !rinci!le and t e 3undSs rule of maximum multi!licit. 1. Au(#au "rin$i"le6 It states that the or%itals are filled in order of their increasin eneries. This rule has two sub rules6 a) The arious orbitals are filled in the increasin" order of their (n9) alue. b) If two orbitals hae the same (n ) alues, the orbital with the lower n alue is fil led first. %. Pauli0s E$lusion Prin$i"le It states that no two electrons i an ato can have the sae set of four 8uantu nu%ers. i.e. an orbital can accommodate a maximum of onl 2 ele trons with o!!osite s!in. 2. Hun'0s rule o( +ai+u+ +ulti"li$it* It states that electron pairin taes place onl$ after partiall$ fillin all the dee erate or%itals. 1#. Which of the followin set of 8u ntu nu%ers are not allowed? i)
n % , l % , m % <, s % 9R
ii)
n % 2, l % 1, m % , s
iii)
n % 1, l % , m % , s
9R
i)
n % , l % , m % , s
9R
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Ans6 3ere i and i are not allowed. In i n% and l % . The alue of l is alwas less than n. i.e. if n%, the !ossible l alues are ,1 and 2. In i, n % . It cannot be !ossible, because the alues of n are 1,2,,4,.
2. CLASSIFICATION OF E EMENTS AND PERIODICITY IN PROPERTIES 1. Write a note on Mendeleev9s pe iodic ta%le. Uimitri $endelee classified the elements in the increasin" order of their atomic wei"hts. 3e !ro!osed a "erio'i$ la3 which states that K T!e "ro"erties o ele+ents are t!e "erio'i$ (un$tions o( t!eir ato+i$ 3ei)!ts.V That is, when elements are arran"ed in the increasin" order of their atomic wei"hts, their !ro!erties r !eat after a re"ular interal. $endelee arran"ed elements in hori@ ntal rows (!eriods) and ertical columns ("rou! ). The elements with similar !ro!erties are arran"ed in the same "rou!. 3e arran"ed elements mainl based on the s imilarities in the em!irical formulae and the !ro!erties of the com!ounds formed b the elements. %. 4!at are t!e Merits o( Men'eleev0s "erio'i$ ta#le 1) It was the first com!rehensie c lassification of elements. 2) 3e corrected the wron" atomic ei"hts of some elements and !laced them in c rrect !osition in the !eriodic table. ) 3e left acant !laces for undisc ered elements and !redicted some of their !ro !erties. 4) 'lements with similar !ro!ertie are !laced in the same "rou!. 3. What are the draw%acs of Mendeleev9s periodic ta%le? i. 'lements with dissi ilar !ro!erties are found in same "rou!. ii. 3e could not "ie a exact !osition for hdro"en. iii. 3e could not "ie e act !osition for 5anthanoids and Actinoids and also for isoto!es. i. $endeleeSs !eriodic table did not strictl obe the increasin" order of atomic wei"hts. !. State Modern eriodic law. Who proposed this law? $odern !eriodic law states that the physical and chemical properties of elements are the periodic functions of their atomic numbersV. This is law was !ro!osed b $osele. ". ;'plain the different %locs in odern periodic ta%le. There are 4 blocs in modern !e riodic table. The are s bloc, ! bloc, d bloc and f bloc. i. T!e s #lo$- ele+ents These are elements in which the las electron enters in the outer most s sub shell. T e include elements of the "rou!s 1 1 2 and 2. Their "eneral outer electronic co fi"uration is ns or ns . The are all reactie metals with low ioni@ation enthal!ies.
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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ii. T!e " #lo$- ele+ents These are elements in which the last electron enters in the outer most ! sub shell. The i nclude elements of the "rou!s 1 to 2 1 to 10. The are also called Re"resentative ele+ents. Their "eneral outer electronic confi"u ration is ns n! . iii. T!e ' #lo$- ele+ents These are elements in which the las electron enters in the !enultimate d sub shell. he include elements of the "rou!s to 12. The are also called Trasition el +ents, since the show a transition (chan"e) fr m the most electro!ositie s bloc 1 to 1 to 2 elements to the least electro!ositie ! bloc elements. Their "eneral outer electronic co fi"uration is (n<1)d ns . iv. T!e ( #lo$- ele+ents th These are elements in which the las electron enters in the anti
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Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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1#. Chlorine has hiher neative electron ain enthalp$ than fluorine. Wh$? #r, 'lectron "ain enthal! o fluorine is less ne"atie than chlorine. JhZ nd This is because, when an electron is added to , it enters into the smaller 2 shell. Uue to the smaller si@e, the rd electron suffers more re!ulsion from th other electrons. *ut for Cl, the incomin" electr n "oes to the lar"er shell. :o the electronic re!ulsion is low and hence Cl adds electron more easil than . 1. ;lectron ain enthalp$ values of no%le ases are
6. CHEMICAL BONDIN7 AND MOLEC&LAR S R&CT&RE 1. State octet rule. What re its liitations? This rule was !ro!osed b 5ewis nd Possel. Accordin" to this rule, atoms underg chemical reaction in order to attain octet of electrons in the valence s ell. Or, atoms containing electrons in their valence shell are stable. Li+itations o( O$tet rule 1) It could not ex!lain the stabilit of com!ounds containin" less than 0 electrons a round the central atom. '.". 5iCl, *e32, *Cl etc. 2) It could not ex!lain the stabilit of molecules containin" odd number of electrons lie N#, N# 2 etc. ) It could not ex!lain the stabilit of molecules containin" more than 0 electrons a round the central atom (i.e. ex!anded octet). '.". 7 , :, 32:#4, I; etc. 4) #ctet rule is based u!on the che mical inertness of noble "ases. *ut some noble ases lie xenon and r!ton form com!ounds with and #. ) This theor does not account fo the sha!e of molecules. ) It does not ex!lain the relatie s tabilit of the molecules. 2. Define Dipole oent. 0ive its unit. The !olarit of a molecule is ex! ressed in terms of dipole moment ([). It is defin d as the product of the magnitude of charge at one end () and the distance between the charges (r . $athematicall, 8 9 : r. The unit of di!ole moment is Cou lomb metre (Cm). *ut it is usuall ex!ressed in t he unit Uebe (U). 3. Bhe dipole oent of e, 2 is
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!. Bhe dipole oent of , 3 is
". -onia (46 3 ) has hiher dipole oent than 4, 3 eventhouh , is ore electroneative than 6. wh$? This is because in the case of N , the orbital di!ole due to lone !air is in the sa e direction as the resultant di!ole moment of the three N ? 3 bonds. *ut i N, the orbital di!ole is in the o!!osite directi n to the resultant di!ole moment of the three N< bonds. :o the di!ole m ments "et !artiall cancelled.
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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#. State ,aEan9s rule reardin the partial covalent character of an ionic %ond. The !artial coalent character of ionic bonds was ex!lained b aBans in terms of the followin" rules6 1) The smaller the si@e of the catio and the lar"er the si@e of the anion, the "reate r the coalent character of an ionic bond. 2) The "reater the char"e on the c tion, the "reater the coalent character of the i nic bond. n ) or cations of the same si@e and char"e, the ion with electronic confi"uration (n< 1)d ns is more !olarisin" than the 2 ion with a noble "as confi"urati n (ns n! ). . What are the ain pos ulates of valence shell electron pair repulsion ( S;) theor$? This theor was !ro!osed b :id"wic and 7owell and later modified b Nholm and +illes!ie. The im!ortant !ostulates of this theor are6 1) The sha!e of the molecule de!ends on the number of alence shell electron !airs (-:'7=s) around the central atom. 2) The alence shell electron !airs re!el each other. ) In order to reduce the re!ulsion , the electron !airs sta at maximum distance. 4) 7resence of lone !airs of electron causes distortion in the ex!ected "eometr of the molecule. ) The re!ulsion between two lon !airs of electrons is different from those betwe en two bond !airs or between a lone !air and bond !air. The re!ulsion decreases in the order lone !air < lone !air Y lone !air < bond !air Y bond !air < bond !air. ) As the an"le between the electr on !airs increases, the re!ulsion decreases. *. ;'plain the shape aonia and water olecules on the %asis of FS; theor$. In ammonia, the central atom N has alence electrons ( ;N ? 2,). Amon" these electrons, three are used for the formation of bonds with hdro"en atoms and the remainin" 2 electrons sta as lone !air s. :o there are 4 -:'7s. 3ence the ex!ected sha!e of the molecule is tetra edral. *ut due to the !resence of lone !airs, the sha!e is distorted to trian"ular !ramid and the bond an"le chan"es to 1; . In water, the central atom # has alence electrons ( 0# ? 2,). Two of t em are used for the formation of bonds with hdro"en atoms and the re ainin" 4 electrons sta as lone !airs. :o there ar e 4 -:'7s. 3ence the ex!ected sha!e of the molecule is tetrahedral. *u t due to the !resence of 2 lone !airs, the sha!e i s distorted bent or an"ular or inerted QS sha!e and the bond an"le c an"es to 14. . +. Define 6$%ridisation. What ar the iportant characteristics of 6$%ridisation It is the !rocess of inter mixin" of atomi orbitals hain" sli"htl different ener"ies to for m new orbitals hain" euialent ener" and identical sha!e. The new or itals formed are called hbrid orbitals.
N I . E V i L S S H
The im!ortant characteristics of hb idisation are6 1) 2) ) 4)
The number of hbrid orbitals f rmed is eual to the number of atomic orbitals nder"o hbridi@ation. The hbrid orbitals are alwas e uialent in ener" and identical in sha!e. The hbrid orbitals are more eff ectie in formin" stable bonds than the !ure atomic orbitals. The hbrid orbitals are directed to some fixed !ositions in s!ace. :o the t!e of bridi@ation "ies the sha!e of the molecule. 1&. ;'plain the eoetr$ of Cl " olecule and account for its hih reactivit$. In 7Cl, !hos!horus atom is in s d hbridisation. :o the molecule has tri"onal bi !ramidal sha!e with bond an"les 12 and .
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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In 7Cl, three 7
N I . E V i L S S H
12. Molecular or%itals are fored %$ t e linear co%ination of atoic or%itals (LC-5). 0ive the salient features of olecular or%ital theor$. i) In molecules, the electrons are !res nt in some s!ecial t!e of orbitals called molec lar orbitals ($.#s). ii) The atomic orbitals (A.#s) of com!a rable ener" and !ro!er smmetr combine to f rm molecular orbitals. iii) Atomic orbitals are monocentric, w ile molecular orbitals are !olcentric. i) The number of molecular orbitals formed % the number of atomic orbitals combined. i.e. if 2 atomic orbitals combined, 2 molecular orbitals are formed. #ne i s called bondin" molecular orbital (*$#) and th e other is called anti
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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3ere there are 2 un!aired e lectrons. :o it is !arama"netic in nature. 1. Define h$droen %ondin with e'a ple. ;'plain the different t$pes of 6/%ondin. The wea attractie force between 3dro"en atom of one molecule and electro e"atie atom (lie , # or N) of the same or different molecule is terme d as 3dro"en bond. e.". 3dro"en bondin" in water
N I . E V i L S S H
3?# .. 3?#.3?#3?# 3 3 3 3 There are two t!es of bonds< inter molecular 3
<. STATES OF MATTER 1. State 7o$le9s law. 0ive its athe tical relationship. Draw the raphical representation.
It states that at constant temperat re, the volume of a fixed mass of gas is inve sely proportional to its pressure. Mathematically, P
α 1/V
P = k x 1/V, where k is th proportionality constant. Or, PV = k, a cons ant
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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P
P
PV PV = a constant
V
1/V
2. 4ae the different t$pes of van de Waal9s forces. Ans6 5ondon force, di!ole
N I . E V i L S S H V
0
-273.15 C
0
0
Temperature (in C)
". What is a%solute
The lowest hypothetical or imagi ary temperature at which gases are suppose to occupy zero volume is called Absolute zero of temperature. #. State -voadro9s law.
It states that eual olumes of a ll "ases under the same conditions of tem!eratu re and !ressure contain eual number of moles or molecules. . What are isother and isochore?
A "ra!h obtained at constant tem!e rature is called isotherm and a "ra!h obtained a t constant olume is called isochore. *. 4ae the as law which ives the relationship %etween the pressure and tepera ure of a fi'ed aount of as at constant volue. Draw the raph t illustrate the a%ove as law.
Ans6 +a<5ussacSs law.
P
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0
T (in Kelvin)
+. Derive ideal as e8uation. The combination of the three "as laws (*oleSs law, CharlesS and Ao"adro l w) "ie a sin"le euation which is nown as i'eal )as e>uation. Accordin" to *oleSs law6 - > 1/7 (At constant T and n) Accordin" to CharlesS 5aw6 ∝ T (At constant ! and n) Accordin" to Ao"adro 5aw6 - ∝ n (At constant ! and T) #n combinin" these three laws we "et6 - ∝ n x T x 1/7 #r, - % = x n x T x 1/7 (where = is a constant called universal )as $onstant) #r, P, 9 nRT .. (1) This euation is nown as i'eal )as e>uation. 1&. Write down the values of R in two different units.
1. 2. 3. 4.
L atm/K/mol L bar/K/mol Pa m /K/mol J/K/mol
0.0821 0.083 8.314 8.314
N I . E V i L S S H
11. State Dalton9s law of artial pressu es. 0ive its application.
$his law states that at constant tem erature, the total pressure exerted by a mixture of non+reacting gases is equal to the sum of the partial pressures of t e component gases. UaltonSs law can be used to calculate the !ressure of a "as
collected oer water surface.
12. What are the postulates of Ginetic
olecular theor$ of ases?
The im!ortant !ostulates of this the or are6 i. ii. iii. i. . i. ii. 13.
'er "as contains a lar"e number of minute and elastic !articles (atoms or molecul s). The actual olume of the molecules is ne"li"ible com!ared to the olume of the "as. There is no force of attraction betw en the "as !articles. The !articles of a "as are in constan and random motion in strai"ht line. Uurin" this motion the collide with each other and also with the walls of the container. The !ressure of a "as is due to the all collisions of the !articles. All collisions are !erfectl elastic. i.e . the total ener" of !articles before and after co llisions remains the same. At an !articular time, different !ar icles of a "as hae different s!eed and hence different inetic ener". The aera"e inetic ener" of "as m olecules is directl !ro!ortional to absolute tem erature. Wh$ do real ases deviate fro ideal as e8uation?
The deiation from real "ases from i deal behaiour is due to two wron" assum!tion of inetic theor of "ases. The are6 1. The actual olume of the molecules is ne"li"ible com!ared to the olume of the " as. 2. There is no force of attraction be tween the "as !articles. These two assum!tions become ron" at high pressure and low temperature. 1!. Write the e'pression for copressi ilit$ factor. What is its value for an ideal as?
The com!ressabilit factor (^) % 7-/n=T or ideal "as ^ % 1 at all tem!eratur and !ressures. 1". Write the van der Waal9s e8uation f states. ;'plain the ters.
an der JaalSs euation is ?P @
%
%
a, ; ?, n#; 9 nRT
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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Jhere 7 is the !ressure of the "as,
is the olume, = is the uniersal "as constant, T is the absolute tem!erature, n is
the no. of moles, QaS and QbS are calle d an der JallSs constants. 1#. Define 7o$le point. The tem!erature at which r al "ases obe ideal "as euation oer an a!!reciable ran"e of !ressure is called *ole tem!erature or *ole !oi t. 1. What is ean %$ noral %oilin po nt and standard %oilin point?
At 1 atm !ressure the boilin" !oint is called nor+al #oilin) "oint. If !ressure is 1 bar then the boilin" !oint is called stan'ar' #oilin) "oint. The normal oilin" !oint of water is 1 DC (; P) and its st ndard boilin" !oint is . DC (;2.
P). 1*. -t hih altitudes a pressure cooer is used for cooin food. Wh$?
At hi"h altitudes (hei"hts) atmos!heric !ressure is low. Therefore liuids at hi"h altit udes boil at lower tem!eratures than at sea leel. :ince water boils a t low tem!erature on hills, the !ressure cooer i s used for cooin" food. 1+. Li8uid drops assue spherical in s ape. Wh$?
'er liuid tries to reduce their en r" b decreasin" the surface area. or a "ien olume s!here has the minimum surface area. :o liuid dro!s assum s!herical sha!e.
N I . E V i L S S H
2&. Define surface tension. What is its SH unit?
It is defined as the force actin" !er u nit len"th !er!endicular to the line drawn on th e surface of liuid. Its :I unit is N m 21. What are the factors affectin visc sit$ of a li8uid?
-iscosit de!ends on tem!erature and molar mass of the substance. It decrease s with tem!erature and increases with molar mass.
. THERMODYNAMICS
1. What are e'tensive and intensive p operties? 0ive e'aples.
'xtensie !ro!erties are !ro !erties which de!end on the amount of matter resent in the sstem. '.".6 -olume (), len"th (l), breadth ( b), hei"ht (h), internal ener" (_), enthal! (3), ntro! (:), +ibbSs ener" (+), heat ca!acit etc.
Intensie !ro!erties are !ro!erties
hich are inde!endent of the amount of matter !resent in the sstem.
'.". 6 Tem!erature (T), 7ressure (7), -olume (-), densit, refractie index, molar hea ca!acit, iscosit, surface tension etc. 2. Define state function and path func tion.
A function or a !ro!ert tha t de!ends onl on the initial and final state of a stem and not on the !ath followed is called a state function. '.".6 T, 7, , _, 3, :, + etc.
7ath functions are !ro!erties which de!end on the !ath followed also. '.". heat () nd wor (w) 3. State the first law of therod$na cs. 0ive its atheatical for.
It states that ener" can nei ther be created nor be destroed. #r, the total e ner" in the unierse is alwas a constant. $athematicall G_ % 9 !. 0ive the relationship %etween I6 and IJ.
G3 is related to G_ as
G3 G_ 9 7G-
". Define std. enthalp$ of foration. ive the std. enthalp$ of foration of 52 olec le.
The enthal! of formation in th standard state (20P T, 1 bar 7 and at stable st te of a""re"ation) is called std. 0
enthal! of formation. y convention, standard enthalpy for formation, - f / , of an e ement in its reference state is ta!en as ero. :o the std. enthal! of form ation of # 2 is @ero.
#. State 6ess9s law of constant su tion. 0ive an$ 2 applications.
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The law states that the total enthal! chan"e for a !hsical or chemical !rocess is the same whether the reaction tain" !lace in a sin"le ste! or in seeral ste!s. #r, the total enthal! chan" e for a !rocess is inde!endent of the !ath followed. It is used for determinin" std. enthal! of combustion and bond enth al!. . Define lattice enthalp$. The lattice enthal! of an ionic co !ound is the enthal! chan"e when one mole o f an ionic com!ound dissociates into "aseous ions. *. Construct an enthalp$ diara for he deterination of lattice enthalp$ of sodiu chloride. 5 attice enthal! of NaCl is d etermined b *orn<3aber ccle. Na(s) 9 R Cl 2(") ` NaCl(s) This inoles the followin" ste!s6 i. Conersion of solid sodium atom to "aseous sodium atom. The ener" chan"e inoled in this !rocess is called sublimation ener". Na(s) ` Na(") Gsub3 ii. Conersion "aseous sodium atom to "aseous sodium ion. The ener" chan"e in this rocess is called ionisation enthal!. 9 Na(")` Na (") Gi3 iii. Conersion of "aseous chlorine olecule to "aseous chlorine atom. The ener" han"e durin" this !rocess is called bond dissociation enthal!. Cl2(")` 2Cl(") Gbond3 R Cl2(") ` Cl(") R Gbond3 i. Conersion of chlorine atom to hloride ion. The ener" chan"e inoled in this rocess is called electron "ain enthal! (Ge"3 ). < Cl(") ` Cl (") Ge"3 9 < . 7acin" of Na (")and Cl (") to form NaCl(s). the ener" chan"e in this !rocess is call ed lattice enthal! (G lattice3 ) 9 < Na (") 9 Cl (") ` NaCl(s) Glattice3 The different ste!s can be re!resented i n a cclic for as follows6 Gf 3 9 < Na(s) 9 R Cl2(") Na Cl (s)
N I . E V i L S S H
Xsub3
RXbond3
Na(")
Xi3
Cl(")
<
<
9e Xe"3
9 (")
Glattice3
<
Na
Cl (")
* a!!lin" 3essSs law we c n write6 G f 3 % Gsub3 9 Gi3 9 R Gbond3 9 Ge"3 orm this lattice enthal! can be de termined as6 Glattice3 % Gf 3 ? EGsub3 9 Gi3 9 R G ond3 9 Ge"3 O
Glattice3
5attice enthal! of NaCl is determin d usin" *orn<3aber ccle as follows6
Glattice3 % Gf 3 ? EGsub3 9 Gi3 9 R Gbond3 9 Ge"3 O +. What are spontaneous processes? ive e'aples. %t is a process that ta!es place without the help of any external agency . All natural ! rocesses are s!ontaneous. '.". flow
of water from hi"h leel to low leel , flow of heat from hot bod to cold bod, inter
ixin" of "ases, burnin" of fuels,
meltin" of ice, ea!oration of water etc. 1&. What are the criteria for spontaneous process?
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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Uecrease in ener" and increase in disorderness. 11. Define entrop$. What is its unit?
It is a easure of deree of disorde ness or randoness of a s$ste. The unit of entro! and entro! chan"e is W/P/mol. 12. Define 0i%%9s ener$. 0ive the crite ia for spontaneit$ of a process in ters of free ener$ chane (0).
It is defined as the maximum amount of available energy that can be converted to useful wor! . or a !rocess to be s!ontaneous, its X+ should be ne"a ie. 13. What are the conditions for 0 to %e neative?
i)
If X3 is ne"atie and X: is 9e, X+ is alwas ?e and the !rocess is alwas s!onta neous.
ii)
If both X3 and X: are !ositie, X+ will be ?e when TX: Y X3. This is !ossible at hi"h tem!erature.
iii)
If both X3 and X: are ne"atie, X+ will be ?e when TX: X3. This is !ossible at low tem!erature.
. E:&ILIBRI&M 1. 4rite t!e e"ression (or e>uili# iu+ $onstant (or t!e reaction i) H% @ I% %HI an' ii; N% @ 2H% %NH2. 2 i) Pc % E3IO E32OEI2O 2 ii) Pc % EN3O EN2OE32O 2. What is the relation %etween Gc and Gp? Xn P! % Pc.(=T) 3. 0ive an$ 3 characteristics of e8uili%riu constant. i. 'uilibrium constant is !!licable onl when the concentrations of the r actants and !roducts hae attained their euilibrium state. ii. The alue of euilibrium constant is inde!endent of the initial concentrations of reactants and !roducts. iii. The alue of euilibrium constant de!ends on tem!erature.
N I . E V i L S S H
!. State Le/Chatlier rinciple. It states that wheneer there is a chan"e in concentration, !ressure or t m!erature of a sstem at euilibrium, the sstem will tr o readBust in such a wa so as to cancel the effe t of that chan"e. ". 6ow do the effect of chane in oncentration teperature and pressure affect the rate of cheical reaction? An increase in concentratio n of reactants increases the rate of forward rea tion (i.e. the euilibrium is shifted to the forward direction) and an increase in concentration of !roducts increase the rate of bacward reaction. Accordin" to 5e ChatlierSs ! rinci!le, increase in tem!erature faours endot ermic !rocess and decrease in
tem!erature faours exothermi !rocess.
Jhen the !ressure incr ases, the euilibrium is shifted to that direction in which no. of moles decreases. #.
Write the -rrhenius concept of acids and %ases. 9
9
Accordin" to this conce t acids are substances which "ie hdro"en ion 3 ) or hdronium ion (3 # ) in <
aueous solution and bases are substances which "ie hdroxl ion (#3 ) in au ous solution. 9
e.". 3Cl is an acid since it !rodu es 3# in aueous solution. 3Cl(l) 9 32#(l) ;.
3#
═
9
(a)
<
Cl (a)
Write 7ronsted concept of acid and %asesZ ccording to this conce t acids are proton (/ donors and bases are (/ acceptors. 9 < or exam!le in the reaction N3 (l) 9 32#(l) N34 (a) 9 #3 (a) 9 9 9 < 3ere N3 is a base since it acce!ts an 3 ion to form N3 4 and 32# is an acid sinc it donates an 3 ion to form #3 . 9 < In the reerse reaction, N3 4 is n acid and #3 is a base. What are conEuate acid %as pairs? ═
*.
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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Acid< base !air that differs b o l one !roton is called a conBu"ate acid ? base ! air. An acid formed from a base is c lled conBu"ate acid and a base formed from an cid is called conBu"ate base. In "eneral, Acid ? 39 ` ConBu" te base *ase 9 39 ` ConBu"ate acid +.
1&.
11.
12.
13.
1!.
State Lewis concept of acids an %ases. Accordin" to this conce t acids are electron !air acce!tors and bases ar electron !air donors. :ubstances which donate electr n !air are called 5ewis bases and substances w ich acce!t electron !air are called 5ewis acids. 9 9 29 'xam!le for 5ewis acids are * , AlCl, 3 , Co , $" etc. < < < 'xam!le for 5ewis bases are N3 , 32#, #3 , Cl , *r etc. Define ionisation constant of water or ionic product of water. What is its value at 2+*G? It is defined as the product of th molar concentration of hydrogen ion (hydronium ion and hydroxyl ion in water or <14 in any aqueous solution . At 20 , Pw % 1 Define 6 . It is defined as the ne"atie lo"arithm of the hdro"en ion or hdronium ion concentration in moles !er litre (i.e. molarit). 3 9 i.e. ! %
N I . E V i L S S H
═
1".
1#.
:
: 9
:
<
Ps! % EA" OECl O %:x:%: <
2 < 2
:ince : % 1. x 1 , Ps! % (1. x 1 ) % 1.1%2 11 M%
G. REDO REACTIONS 1. Define the electronic concept o o'idation and reduction.
Accordin" to this conce!t oxidation is the process of removal (losing of electron and reduction is the process of addition (gaining f electron. 2. Define the o'idation nu%er concept of o'idation and reduction.
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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Accordin" to this conce! , oxidation is the process of increase in the o xidation number of an element and reduction is the process o f decrease in the oxidation number of an element . 3. What are Stoc notations? Jsin Stoc notation represent the followin copounds i) 6-uCl ! ii) Mn52
:toc notations are some notations used to re!resent the oxidation number of a metal in a com!ound. Accordin" to this, the oxidation number is re!resented in =o an numeral in bracets after the smbol of the metal in the m lecular formula. :toc notations for 3AuCl 4 is 3Au(III)Cl4 and that for $n# 2 is $n(I-)# 2. !. What is a disproportionation reaction? 0ive an e'aple.
Uis!ro!ortionation r action is a s!ecial t!e of redox reaction in
hich an element in one
oxidation state is simultaneo sl oxidised and reduced. '.". The decom!osition of hdro"en !eroxide.
3ere the ox"en of !eroxide is in ?1 state and it is conerted to @ero oxid tion state in # 2 and ?2 oxidation state in 32#.
N I . E V i L S S H
". ,luorine reacts with ice as ive %elow 6 25(s) K , 2() reaction.
6,() K 65,(). Austif$ that this is a redo'
Ans6 3ere the oxidation number of #x"en increases from <2 to 91 and that of is decreased from @ero to <1. :o this is a redox reaction.
#. Write the redo' reaction involv d when etallic co%alt is placed in a nicel sul hate solution.
Co 9 Ni:#4
Co:#4 9 Ni
. Hn the reaction %(s) K %52(s) K 26 2S5!(a8) o'idised ii) Su%stance reduce
2 %S5!(s) K 2 6 25(l) Hde tif$ the followin i) Su%stance
iii) 5'idisin aent iv) educin aent.
Ans6 3ere the #xidation number of 7b increases from @ero to 92. :o 7b is oxid ised and it is the reducin" a"ent. Also the oxidation number of 7b #2 decreases from 94 to 92. :o 7b# 2 is reduced nd hence it is the oxidisin" a"ent. *. Cheical reactions which invol e o'idation and reduction are called redo' rea tions. Bhe un%alanced e8uation in the ionic for of a redo' reacti n is shown %elow. ,e2K(a8) K Cr 25 2/(a8) ethod.
,e3K(a8) K Cr 3K(a8). 7alance this e8uation %$ o'idation nu%er
aci ic ediu
Ans Ste" 16 Assi"n the oxid tion number of each element and identif th atoms which under"o chan"e in
oxidation number. Ste" % Calculate the chan e in oxidation number !er atom and euat them b multi!lin" with
suitable coefficients. 3ere th oxidation number of iron is increased b 1 nd that of Cr is decreased b . (since there are two Cr atoms, o xidation number decresed b ). :o multi!l e 29
2<
9
e (a) 9 Cr2#; (a)
2
2<
b and Cr 2#; b 1.
9
e (a) 9 Cr (a).
Ste" 2 *alance all the at ms exce!t ox"en and hdro"en. 29
2<
9
e (a) 9 Cr2#; (a)
9
e (a) 9 2 Cr (a).
Ste" 66 Now euate the ionic char"es on both sides of the euation. :i ce the reaction taes !lace in
acidic medium, use 39 ions to balance char"es. 3ere the net ionic char"e n 53: is 91 and that at =3: is 9
24. :o add 14 3 9 on 53: to e uate ionic char"e. 29
2<
9
e (a) 9 Cr2#; (a) 9 143
9
9
e (a) 92 Cr (a).
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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Ste" <6 Now mae the nu bers of hdro"en atoms in the ex!ression o the two sides eual b addin"
water (32#) molecules to the reactants or !roducts. Now, also chec the umber of ox"en atoms. 29
e (a) 9 Cr2
;
2<
(a) 9 14 3
9
9
9
e (a) 9 Cr (a) 9 ; 3 2#
+. What are the rules for assinin o'idation nu%er of an eleent?
a) The oxidation number of all elements in the free or the uncombined state is @ero. or e.". oxidation number of 3 2, #2, Cl2, #, 74, 0, Na, $", Al etc. is @ero. b) or sim!le ions, the oxidation number is eual to the char"e on the ion. T us Na9 ion has an oxidation number of 91, $" 29 ion 92, 9 ion 9, Cl ? ion ?1, #2? ion ?2 and so on. c) All alali metals hae oxidation number of 91 and all alaline earth metals hae an oxidation number of 92. Aluminium shows an oxidation number of 9 in all of its com!ounds. d) The common oxidation number of ox"en is ?2. *ut in !eroxides (e."., 3 2 2, Na2#2), oxidation number of ox"en is ?1 and in su!eroxid s (e."., P#2, =b#2), it is ?R. In ox"en difluoride (#2) and diox"en difluoride (#22), the ox"en is assi"ned an oxidation number of 92 and 91 res!ecti l. e) The common oxidation number of hdro"en is 91. *ut in hdrides, 3 shows an oxidation number of <1. f) The common oxidation number of halo"ens is <1. luorine shows onl <1 o xidation number in all of its com!ounds. *ut other halo" ns show !ositie oxidation numbers also in heir oxides and oxoacids. ") The al"ebraic sum of the oxidation number of all the atoms in a com!ound is @ero. h) In !olatomic ion, the sum of the oxidation numbers all the atoms is eual to the char"e on the ion.
N I . E V i L S S H . HYDRO7EN
1. Austif$ the position of h$droen in the periodic ta%le.
th
3dro"en shows resem lance with both Alali metals of the first "rou! nd halo"ens of the 1; "rou!. 5ie alali metals it has one electron in the outer most shell and forms uni!ositie i ns. 5ie halo"ens, it reuires onl one electron to com!lete the alence shell confi"uration. :o it "ains one electr on to form unine"atie ion. At the same time it shows some diffe rences from alali metals and halo"ens. :o it is ! laced se!aratel in the !eriodic table.
2. What is water as or s$n as?
A mixture of C# (carbon monoxide) and 32. 3. What is Ncoal asification9?
The !rocess of !roducin" sn"as from coal is called Ocoal asificationO . C(s) 9 32#(") 1 ;P C#(") 9 3 2(")
!. 6ow is dih$droen produced $ Nwater as shift reaction9?
The !roduction of dihdro"en can be increased b reactin" carbon mon xide of sn"as mixtures with steam in the !resence of iron chrom te as catalst. This is called water/as shift rea tion. C#(") 9 32#(") ;P, ca alst C#2(") 9 32(") ". Write an$ two uses of dih$dr en. a) It is used as a roce fuel in s!ace research. b) It is used in fuel cell for "eneratin" electrical c) It is used in the man ufacture of anas!ati fat b the hdro"enation f e"etable oils. #. Water is an aphoteric su%st nce. Austif$. Jater can act both as acid and base. :o it is an am!hoteric substance. < 9 e.".6 32#(l) 9 N3(a) #3 (a) 9 N34 (a) 9 ? 32#(l)932:(a) 3 (a) 9 3: (a) Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
Page 1&
In the first e.". water acts as a acid and in the second it acts as a base. . Which are the different t$pes of h$drides? 0ive one e'aple for each. There are three t!es o hdrides ? ionic hdride (e.". Na3), coalent h ride (e.". 3 2#) and metallic hdride (e.". -3.) *. What is ean %$ hardness of ater? What is the reason for hardness of water? Jater which does not easil form lather with soa! is called hard water. I t is due to the !resence of calcium
and ma"nesium salts in the fo m chlorides, sul!hates and bicarbonates. +. 6ard water is harful for %oil rs. Wh$?
#n boilin" hard water, the soluble $"(3C#)2 is conerted into insoluble $"(#3)2 and Ca(3C#)2 is chan"ed to insoluble CaC# . These salt are de!osited in the boilers in the form of scale s. This reduces the efficienc of boilers. 1&. What is ean %$ teporar$ hardness? ;'plain the different ethods used fo its reoval?
3ardness which can be emoed b sim!le boilin" is called tem!orar h rdness. It is due to the !resence of bicarbonate of calcium and ma"nesium. The followin" methods are used to remoe tem!orar hardness. 1. 7oilin6 Uurin" boilin", the solu le $"(3C# )2 is conerted into insoluble $"(# )2 and Ca(3C#)2 is chan"ed to insoluble CaC#, which can be r moed b filtration. $"(3C# )2 ⎯⎯⎯⎯`$"(#3)2 9 2C#2 Ca(3C#)2 ⎯⎯⎯⎯`CaC# 9 32 9 C#2 2. Clar9s ethod 6 In this method alculated amount of lime is added to hard water. It !reci!itates out calcium carbonate and ma"nesium hdr xide which can be filtered off. Ca(3C#)2 9 Ca(#3)2 ` 2CaC# 9 232# 11. What is ean %$ peranent ardness? ;'plain the different ethods used for its reoval? 3ardness which cannot be remoed b boilin" is called 7ermanent hard ess. It is due to the !resence of soluble chlorides and sul!hates of calcium and ma"nesium in water. It can be remoed b the followin" methods6 1. Treat+ent 3it! 3as!in) so'a ( odium carbonate)6 Jashin" soda reacts with soluble calcium and ma"nesium chlorides and sul!hates in hard water to form insoluble carbonates. CaCl2 9 2Na2C# ` CaC# 9 2NaCl $"Cl2 9 2Na2C# ` $"C# 9 2NaCl 2. Cal)on0s +et!o'6 :odium hexa eta!hos!hate (Na7#10) is commerciall called Qcal"onS. Jhen it is added to hard 9 water, the Ca and $" ions in hard water are re!laced b Na ions. . Ione$!an)e +et!o'6 This method is also called @eolite/!ermutit !rocess. ^eoli te /!ermutit is hdrated sodium aluminium silicate which can be written as Na^. Jhen this is added to hard water, excha n"e reactions tae !lace. 29 9 2Na^ 9 $ ` $^2 9 2Na (where $ % $" or Ca) 4. S*nt!eti$ resins +et!o'6 Cation exchan"e resins contain lar"e or"anic molecule with <:# 3 "rou! and are water 9 29 insoluble. Ion exchan"e resin (=:# 3) is chan"ed to =Na b treatin" it with NaCl. The resi n exchan"es Na ions with Ca and 29 $" ions !resent in hard water and ma e the water soft. 29 9 2=Na 9 $ ` =2$ 9 2Na This method is more suitable to "et !ur demineralised water. 12. 0ive the industrial preparatio of 6$droen pero'ide. Industriall it is !re!ared b the auto
N I . E V i L S S H
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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1!. ;'plain wh$ h$droen pero'i e is not stored in lass vessels.
#=, 3dro"en !eroxide is stor d in !lastic essels in dar. JhZ Ans6 32#2 decom!oses slowl on ex!osure to li"ht. 232#2(l) ` 232 (l) 9 # 2(") In the !resence of traces of al ali (!resent in "lass containers), the aboe react ion is catalsed. :o it is stored in wax
Ueuterium oxide (U 2#) is calle hea water. It is used as a moderator in nucle r !ower !lant.
N I . E V i L S S H 1.
THE SBLOCJ ELEME TS
1. -lali etals and their salts ive characteristic colour to non/luinous flae.
h$?
This is because the heat from the flame excites the outer most orbital el ctron to a hi"her ener" leel. Jhen this electron comes bac to the "round leel, the emit the radiation in he isible re"ion. 2. 6ow do alali etals react wit air?
Alali metals react with air to form oxides, !eroxides and su!er oxides. 5i forms onl monoxide, sodium forms monoxide and !eroxide and other alali metals form monoxide, !eroxid and su!er oxide. 3. Solutions of alali etals in li8 id aonia are %lue in colour. Wh$?
The alali metals dissole in li uid ammonia to "ie dee! blue solutions. The bl ue colour of the solution is due to the formation of ammoniated electron.
!. 0ive an$ two anoalous prope ties of Lithiu.
a) 5i is the least reactie but he stron"est reducin" a"ent amon" all the alali metals. b) It forms onl monoxide wi h ox"en.
". What is ean %$ diaonal relationship? 0ive an$ two siilarities in properties shown %$ Lithiu and Manesiu.
The similarit in !ro!erties shown b dia"onall !laced elements of second and third !eriods in modern !eriodic table is called dia"on l relationshi!.
5i shows the followin" similarities in !ro!erties with $" of the second "r ou!. a) *oth react slowl with water. b) The do not form su!eroxi des. #. 4ae the process used for the industrial preparation of sodiu car%onate. ;'plain the process.
:odium carbonate is manufactured b :ola !rocess (Ammonia<:oda 7 ocess). In this !rocess, C# 2 is !assed throu"h a concentrate solution of NaCl saturated with ammonia. Am onium carbonate first formed then conerted to ammonium bicar bonate and finall reacts with NaCl to form Na3 #. 2N3 9 32# 9 C#2 ` (N 4)2C# (N34)2C# 9 32# 9 C#2
2N343C#
N343C# 9 NaCl ` N3 4 l 9 Na3C# :odium bicarbonate crstals a e se!arated and heated to "et sodium carbonat e. 2Na3C# ` Na2C# 9 C
2 9
32#
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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. 0ive an$ two uses of sodiu ca %onate.
a) It is used in water softenin", launderin" and cleanin". b) It is used as a laborator r a"ent. *. What are the uses of sodiu h dro'ide (4a56)?
a) in !etroleum refinin". b) in the !urification of bauxi te c) as a laborator rea"ent. +. 0ive the structure of %er$lliu hloride (7eCl 2 ).
It has a chain structure in the olid state.
1&. 0ive an$ two siilarities in properties (diaonal relationship) shown %$ 7er$l iu and aluiniu.
a) 5ie Al, *erllium is not re dil attaced b acids. b) The chlorides of both the lements hae brid"ed structure in a!our !hase .
N I . E V i L S S H
11. What is 8uic lie and slaed lie? 0ive their uses.
Muic lime is calcium oxide (Ca #) and slaed lime is calcium hdroxide ECa(#3) 2O. Muic lime is used in the manu facture of Na2C# from caustic soda and for the !urification of su"ar. :laed lime is used in white w shin", in "lass main", in tannin", for the !re!ar ation of bleachin" !owder and for !urification of su"ar.
12. What happens when C52 is passed throuh lie water?
Jhen C#2 is !assed throu"h li e water, it turns mil due to the formation of CaC#. #n !assin" C#2 continuousl, the solution beco es clear due to the formation of soluble calciu Ca(#3)2 9 C#2
bicarbonate ECa(3C#)2O
CaC# 932#
CaC# 9 32# 9 #2 ` Ca(3C#)2 13. Coplete the followin reacti ons i)
CaC53 12&&G
ii)
CaC53 K 6 2S5!
?
Ans6 CaC# 12P
?
Ca# 9 C# 2
CaC# 9 32:#4
Ca:#4 9 C#2 9 32#
1!. What is plaster of paris? 0ive its preparation and uses?
It is a hemihdrate of calcium sul!hate. It is obtained when "!sum ECa: #4g232#O is heated to P. 2 Ca:#4.232#
2 Ca:# 4.32# 9 32#
It is used in the buildin" industr , in hos!itals for settin" fracture of bones and for main" statues. 1". What is dead %urnt plaster?
Jhen !laster of !aris (or "!sum) is heated aboe P, it becomes an drous calcium sul!hate (Ca:# 4). This is nown as Q dead burnt p aster S. 1#. laster of paris is used for o ldin statues. Wh$?
#n mixin" with water !l aster of !aris forms a !lastic mass that "ets into a hard solid in to 1 minutes. Uurin" this !rocess its olume in creases. :o it is used for the !re!aration of stat es. 1. What are the aEor roles of t ese 4aK and G K ions in our %od$?
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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9
Na ions !artici!ate in t e transmission of nere si"nals, in re"ulatin" th flow of water across the cell membranes and in the trans!or of su"ars and aminoacids. 9 P ions actiate man e @mes, !artici!ate in the oxidation of "lucose to AT7 and hel!s in the transmission of nere si"nals alon" with sodi m ions. 1*. 0ive the nae of the etal p esent in chloroph$ll.
Ans6 $a"nesium 1+. What is the use of il of a nesia?
Ans6 It is used as an antacid. 2&. What is 7ain soda? 0ive its uses.
:odium bicarbonate (Na3C#) is called bain" soda. It is used as a mild a ntise!tic and in fire extin"uisher.
1. T!e "Blo$- Ele+ents 1. Hn roup 13 eleents ato ic radius increases down the roup. 7ut at ic radius of alliu is less than that of aluiniu. Wh$? This is due to the !resence of c m!letel filled d
N I . E V i L S S H
#. What is 7ora'? What is the ction of heat on it? It is :odium tetra boratedecahd ate with formula Na2*4#;⋅132#. #n heati ", borax first loses water molecules and swells u!. #n further eatin" it turns into a trans!arent liuid, which solidifies into "lass lie material nown as borax bead. . What is 7ora' %ead test? #n heatin" *orax with transition metals, coloured beads are formed. :o borax bead test can be used to identif transition metals. *. - a8ueous solution of %ora' s %asic in nature. Austif$. *orax dissoles in water to "i e Na#3 and orthoboric acid. :ince Na#3 is a stron" alali and orthoboric acid is wea acid, the solution is basi in nature. Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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+. 5rtho %oric acid is ono%asi even thouh it contains three h$droen atos. Wh$? #rthoboric acid is a wea mo obasic non
N I . E V i L S S H
12. What is inoranic %en
Page !
three si"ma bonds with other three arbon atoms. The remainin" electron at each carbon is delocalised in molecular orbitals. This "ies an aro atic character to the molecule. 1. What are water as and pro ucer as. 0ive an$ one of their use? A mixture of carbon monoxide and hdro"en is called water "as or snthesis "as. It is !re!ared b !assin" steam oer red hot coe at about 1 ;P. C(s) 9 32#(") ` C#(") 9 32(") A mixture of carbon monoxide and nitro"en is called !roducer "as. It is !r !ared b !assin" air oer red hot coe at about 12;P. C(s) 9 #2(") 9 N2(") ` C#(") 9 4N (") *oth these "ases are used as industrial fuels. 1*. Suest a reason for the to'icit$ of C5? In C#, there are one si"m and two !i bonds between carbon and ox"en (6C #6). *ecause of the !resence of lone !air on carbon, C# molecule acts as an electron donor and rea ts with metals. :o it can easil form a com!lex with haemo"lobin (carbox haemo"lobin). It is about times stabler than oxhaemo"lobin com!lex. This !reents haemo"lobi in =*C from carrin" ox"en round the bod . 1+. What is dr$ ice? 0ive its use Ur ice is solid carbon dio ide. It is obtained b coolin" C# 2 under !re sure. It sublimes directl to the a!our !hase without liuefin". It oes not wet the surface on which it sublim s. :o it is called dr ice. It is used as a refri"erant for ice
N I . E V i L S S H
*ut in silica (:i#2), each silicon atom under"oes s! hbridisation. 3ere each :i at m is tetrahedrall surrounded b 4 ox"en atoms. :o it has a three imensional networ structure and hence it is a solid. 21. What are silicones? 0ive the r uses? The are a "rou! of or"anosilicon !olmers, which hae (<= 2:i#<) as a re!eatin" unit. The are used as sealant, "reases, electrical insulators and for water !roofin" of fabrics. *ein" biocom!atible the are also used in sur"ical and cosmetic !lants.
12. OR7ANIC CHE ISTRY K SOME BASIC PRINCIPL S AND TECHNI:&ES 1. T!e #on'line (or+ula o( a $ +"oun' is )iven #elo3.
HO 4rite its $on'ense' (or+ula an' )ive t!e I&PAC na+e. Ans6 Condensed formula is 3
CH2CH%CHCH%CH% HCH%CH2 OH
CH2
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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ii;
CH2CH%CH9CHCH% OOH Ans6 i) <$ethloctan
ii) 3ex<
2. Dra3 t!e stru$tures o( t!e (ollo3in) $o+"oun's. i; %2Di#ro+o1"!e *l"entane ii; 6Et!*l1(luoro% itro#enene Ans6 i) C32
ii)
N#2
C23 6. 4rite t!e $o+"lete $on'en e' an' #on' line stru$tural (or+ulae o( %#ro+o#utane. 3 333 Ans6 Com!lete structural for ula6 3
N I . E V i L S S H r
*ond line structure6
<. 4rite t!e stru$tures o( t!e ( llo3in) or)ani$ $o+"oun's. a; %< K Tri+et!*lo$tane #; Heane%6'ione
$; <oo!eanoi$ a$i' Ans
a) C3
c) C3
. T!e I&PAC na+es o( al-anes are #ase' on t!eir $!ain stru$ture. a; 7ive t!e I&PAC na+e o(
CH2 K CH% K CH CH% K CH K CH% K CH2 CH%CH2
CH2
#; Re"resent 1Met!*l2"r "*l$*$lo!eane usin) #on' line notation. @
$; 4!at is t!e t*"e o( !*#ri iation o( C in CH2 5 Also "re'i$t its s!a"e. '; Na+e t!e t*"e o( #on' (ission resultin) in t!e (or+ation o( (ree ra'i als5 Ans6 a) <'thl<
c) 3bridisation6 s!2
sha!e6 !lanar trian"ular
d) 3omolsis or homoltic ond fission . 7ive t!e I&PAC na+es o( t!e (ollo3in) Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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OH
CH2
a; CH2 K CH K CH% K CH% K C K CH2 CH%CH2 #; CH2 K CH% K CH% K C K CH2 O $;
OH Br
Br
Br
Ans6 a) ,
. 4rite t!e #on' line stru$tures o(
N I . E V i L S S H
#; CH2 K CH?OH; K CH% K CH r K CH2 Ans6 a) #3
*r
b)
. 4rite t!e I&PAC na+e o( t!e (ollo3in) CH2 i;
CH2
CH2 K C K CH% K CH CH2 CH2
ii;
CH2 K CH 9 CH K CH % K C
% K
COOH
Ans6 i) 2,2,4
1. 7ive t!e stru$tures o( t!e (ollo3in) $o+"oun's i;
2KEt!*l66'i+et!*l"entane
ii)
Met!*lo$tan2 l Ans6 i)
ii)
C3
11. 4rite t!e I&PAC na+e o( t!e (ollo3in) $o+"oun's CH2
CH%CH2
i;
CH2 K CH K CH K CH K CH2
ii;
?CH2;%CH K CH K CH K CH2 Cl
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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iii;
OH
Ans6 i) 2,4
2
iii)
Cclohexenol
1%. Dra3 t!e stru$ture o( t!e + le$ules re"resente' #* t!e I&PAC na+es a; "ent6en%ol #; 2nitro$*$lo!eane. Ans6
a) C32%C3
N I . E V i L S S H
12. Ho3 +an* 0 an' 0 #on's are "resent in t!e (ollo3in) $o+"oun's5 CH% 9 C 9 CH CH2 Ans. \ bonds and 2
bonds.
16. 4rite t!e I&PAC na+e o( t!e (ollo3in) $o+"oun's CH2 CH% K CH CH% CH OH Ans6
an' CH2 K CH 9 CH CH% C C CH2 and
he!t<2
1<. 7ive t!e I&PAC na+e o( t!e ollo3in) $o+"oun' CH2CH%COCH%CH%COOH Ans6 4
1. 4!at is !o+olo)ous series5
Ans6 A series or "rou! of or"anic com!ounds in which adBacent members are differed b a ?C32 "rou! is called a homolo"ous series.
1. Classi(* t!e (ollo3in) into ! +olo)ous series an' na+e t!e series. C2HG C%H
2
Ans6 Alane ? C30 and C314
All halides ? C23Cl, C43Cl and C3
1G. 4rite t!e )eneral (or+ulae ( t!e (ollo3in) !o+olo)ous series. i)
Al-*nes
ii; Al$o ols
Ans6 Alnes6 i) C n32n<2,
iii; C!loroal-anes
ii) Alcohols6 Cn32n91#3
iii)Chloroalanes < Cn32n91Cl
1. 4rite all t!e "ossi#le $!ain i o+ers o( t!e $o+"oun' 3it! +ole$ular (o +ula C
3
2. 7ive an* t!ree t*"es o( stru$tural iso+ers. 7ive ea+"les. Ans6 i) 7osition isomerism6 C
1<*utanol
C3
unctional "rou! isomerism6 thanol (C3
Page %
Chain isomerism6 C3
C3
%1. 4rite t!e +eta+ers $orres" n'in) to t!e +ole$ular (or+ula C6H1O. Ans6 C3<#
#; eterol*ti$ (ission
$; Nu$leo"!iles
'; ele$tro"!iles
Ans6 Ho+ol*sis6 It is a t!e of bond fission in which each of the bonded at ms "ets one of the electrons of the shared !air. Heterol*sis6 It is a t!e of bond fission in which the shared !air of electrons remains with one of the !arts. Nu$leo"!ile A rea"ent that brin"s an electron !air is called a nucleo!hile. Ele$tro"!ile A rea"ent that taes awa an electron !air is called an electro!hile. %2. E"lain t!e 'i((erent t*"es ele$tron 'is"la$e+ent e((e$ts in $ovalent #o 's. Ans6
N I . E V i L S S H
In'u$tive e((e$t ?I e((e$t; It i the shiftin" of si"ma electrons throu"h a carbon chain in !resence of an atom or "rou! of atom attac ed to a carbon chain. It is a !ermanent effe t. Ele$tro+eri$ e((e$t ?E e((e$t; It is the shiftin" of H
Resonan$e E((e$t ?R e((e$t; It is defined as Qthe !olarit (char"e) !roduced in the molecule b the interaction of two H
@
@
@
@
%<. Arran)e t!e (ollo3in) $ar#o$ations in t!e in$reasin) or'er o( sta#ilit* ? H2;%CH CH2 ?CH2;2C CH2CH% Ans6 C39 C3
9 )2C3
(C3)C9
%. Cate)orie t!e (ollo3in) (un tional )rou"s into t!ose !avin) @R e((e$t a ' KR e((e$t NH% NO% COOH OH Ans6 9= effect6
Page &
%. ,arious +et!o's (or t!e "uri(i$ation o( or)ani$ $o+"oun's are #ase' o t!e nature o( t!e $o+"oun' an' t!e i+"urit* "resent in i . E"lain t!e "rin$i"le involve' in t!e (ollo in) +et!o's o( "uri(i$ation a; Distillation
#; Stea+ 'istillation
Ans6 a) Distillation This method is used to se!arate (i) olatile liuids from n n<olatile im!urities and (ii) the
liuids hain" sufficient difference in their boilin" !oints. The !rinci!l of this method is that liuids hain" different boilin" ! ints a!orise at different tem!eratures. The a!ours are cooled and the liuids so formed are coll cted se!aratel. b) Stea+ 'istillation This techniue is a!!lied to se!arate substances which are steam olatile and are
immiscible with water. In steam distillation, steam from a steam "ene ator is !assed throu"h a heated flas containin" the liuid to be distilled. The mixture of steam and th olatile or"anic com!ound is condensed and collected. The com!ound is later se!arated from water usin" a se!aratin" funnel. Aniline ? water mixture is se!arated b this method.
N I . E V i L S S H
%G. Ho3 is so'iu+ (usion etra$ "re"are'5 &sin) t!is !o3 3ill *ou 'ete$t !e "resen$e o( Nitro)en Sul"!ur an' Halo)en in an o )ani$ $o+"oun'5
Ans6 Nitro"en, sul!hur and h lo"ens !resent in an or"anic com!ound are detected b KLassaine9s test V. 3ere the or"anic com!ound i fused with metallic sodium in a fusion tube. It is then !lun"ed into distilled water taen in a china dish. The solution is boiled and filtered. The filtrate is nown as sodium fusion extract. * usin" sodium fusi n extract, elements lie N, : and halo"ens c n be detected as follows6 No. 1.
2.
E"eri ent To one !art of sodium fusio extract add freshl !re!ared ferrous sul!hate ( e:#4) solution. 3eated to boilin", cooled and acidifi d with dil. 32:#4. A little of the sodium fusion extract is acidified with dil. 3N# and then siler nitrate (A"N#) is added.
.
O#servation *lue or "reen coloration or !reci!itate (!!t) Jhite !!t solubl in ammonium hdroxide (N34# ) 7ale ellow !!t sli"htl soluble in N34#3 jellow !!t insoluble in N34#3 -iolet colouratio
In(eren$e 7resence of nitro"en 7resence of Chlorine
7resence of *romine 7resence of Iodine 7resence of sul!hur
To a little of the sodium fusi n extract, add sodium nitro!russide solution %. 4rite t!e na+e o( t!e test u e' to 'ete$t nitro)en sul"!ur !alo)ens a ' "!os"!orous "resent in an or)ani$ $o+"oun'. Ans6 5essai"neSs test 2. Or)ani$ $o+"oun's !ave to #e "uri(ie' #e(ore anal*sis. a; 4!i$! t*"e o( li>ui's $an #e "uri(ie' usin) 'istillation un'er re'u$e "ressure5 Su))est an ea+"le. #; Na+e t!e t3o +ain t*"e o( $!ro+ato)ra"!i$ te$!ni>ues #ase' on !e "rin$i"le o( 'i((erential a'sor"tion.
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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$; In t!e Lassai)ne0s test (o !alo)ens t!e* are "re$i"itate' as . '; In 3!at (or+ is nitro)en sti+ate' in t!e Du+as +et!o'5 Ans6 a) 5iuids hain" er hi h boilin" !oints and those, which decom!o e at or below their boilin" !oints. +lcerol can be se!ar ted from s!ent
ii) Thin laer chromato"ra!h. c) :iler halides (A"k) d) $olecular nitro"en (N2) 1. Na+e t!e +et!o' (or esti+ tion o( Halo)en. Ans6 Carius method 2%. E"lain an* one +et!o' (or !e esti+ation o( nitro)en "resent in an or)ani$ $o+"oun'. Ans6 Du+as +et!o' 3ere the or"anic com!ound is heated with co!!er oxid in an atmos!here of carbon dioxide so that free nitro"en, ca bon dioxide and water are !roduced. This mixture of "ases is collected oer an aueous solution of !otassiu hdroxide which absorbs carbon dioxide. Nitro"en is collected in the u!!er !art of the "raduated tube. rom the olume of nitro"en collected, we can d termine the of Nitro"en. . In the Carius method of estimation of halo"en, .1" of an or"anic com!ound "ae .12" of A"*r. ind the
N I . E V i L S S H
!ercenta"e of *r in the com! und. Ans6 rom Carius method,
7ercenta"e of halo"en % Ato ic mass of halo"en x m1 x 1 $olecular mass of A"k x m % 0 x .12 x 1 % 4 100 x .1 26. Di((erent +et!o's are use' to "uri(* or)ani$ $o+"oun's. Na+e an* t!r e +et!o's o( "uri(i$ation. Ans6 :ublimation, Crstallisation and Uistillation.
2<. On $o+"lete $o+#ustion . 6) o( an or)ani$ $o+"oun' )ave .1G) o( CO% an' .116) o( H%O. Deter+ine t!e "er$enta)e $ +"osition o( $ar#on an' !*'ro)en in t!e $ +"oun'. 7ercenta"e of hdro" n % 2 x m1 x 1 % 2 x .114 x 1 % 4. 10 x m 10 x .24 7ercenta"e of carbon % 12 x m2 x 1 % 12 x .10 x 1 % 21. 44 x m 44 x .24 2. Di((erent te$!ni>ues are use (or t!e "uri(i$ation o( or)ani$ $o+"oun's #ase' on t!eir nature. a; Su))est a suita#le +et!o' (or t!e se"aration o( a +iture o( aniline an' 3ater. #; 7ive t!e $!e+i$al na+e ( t!e $o+"oun' res"onsi#le (or t!e #lue $ lour in t!e Lessai)ne0s test (or nitro)en. c) Brie(l* e"lain t!e "rin$i le involve' in JQel'a!l0s +et!o' (or t!e esti+ation o( nitro)en. Ans6 a) steam distillation b) erriferrocanide c) PBeldahlSs method6 3ere t e or"anic com!ound containin" nitro"en is heated with concentrated sul!huric acid. Nitro"en i the com!ound "ets conerted to ammoniu m sul!hate. The resultin" acid Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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mixture is then heated with excess of sodium hdroxide. The liberate ammonia "as is absorbed in an excess of standard solution of sul!huric acid. The amount of ammonia !roduced is determined b estimatin" the amount of sul!huric acid consumed in the reaction. It i done b estimatin" unreacted sul!huric acid left after the absor!tion of ammonia b titratin" it with standard alali solution.
1. What is Wurt< reaction? All halides react with metallic sodium in dr ether to form alan s. This reaction is nown as Jurt@ reaction. 2 =
dr ether
=<= 9 2Nak
N I . E V i L S S H
C3<*r 9 2Na 9 *r
. What is ean %$ 0eoetri al isoeris? Draw the eoetrical isoe s for 2/%utene.
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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The isomerism arisin" due o the difference in the s!atial arran"ement f atoms around carbon
*. What is Lindlar9s catal$st? ive its use. 3artially deactivated alladised charcoal is !nown as Lindlar9s cat l$st . Alnes on reduction with 5indlarSs catalst, we "et cis
N I . E V i L S S H
+. What is the aEor product ored on the addition of 67r to 1/propene 4ae the rule $ou used to choose the aEor product. tate it. Jhen 3*r is added to !ro!ene, we "et 2 !roducts ? 1
3ere the maBor !roduct is de ermined b a rule called Marownioff9s ru e. The rule states that Kwhen an uns$etrical reaent is ad ed to an uns$etrical alene the neative part of the addendu (addin olecule) ets attac ed to the car%on containin lesser nu%er of h$droen atosV 1&. What is pero'ide or Gharas h effect? 0ive an e'aple. In the !resence of !eroxide, addition of 3*r to unsmmetrical al nes taes !lace a"ainst $aronio rule. This is no n as pero'ide or Gharash effect or anti/M rovniov addition reaction. e.". C3
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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% 13. State 6icel9s (!n K 2) P ele tron rule. Accordin" to this rule, Kcclic, !lanar, conBu"ated sstems containin" (4n92) H electrons are aromaticV. Jhere n is the nu ber of rin"s. n ma be 1,2,,. 1!. 6ow will $ou convert sodiu %en
1". 6ow will $ou convert phen l to%en
N I . E V i L S S H
1#. What are electrophilic su%stitution reactions? 0ive eaples. These are reactions in which a wea electro!hile is re!laced b a stro " electro!hile. The im!ortant electro!hilic substitution reactio s are Nitration, :ul!honation, 3alo"enation and riedel
1. Convert %en
*en@ene
Aceto!henone
*en@ene 1*. What is ae'ane or 76 ? 0ive its preparation.
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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*en@ene adds chlorin in !resence of u li"ht to form ben@ene he achloride (*3C). It is also nown as +ammexane or 5indane r .
1+. 6ow will $ou convert %en
N I . E V i L S S H
6. EN,IRONMENTAL CHEMISTR
1. Car%on ono'ide is one of th ost serious air pollutants. Wh$? Carbon monoxide binds to haemo"lobin in blood to form carboxhaemo "lobin. It reduces the ox"en carrin" ca!acit of blood. Thi ox"en deficienc, results into headache, wea eesi"ht etc. 2. What are the aEor ases wh ch contri%ute towards lo%al warin? What an we do to reduce lo%al warin?
+ases lie carbon dioxide, methane, o@one, chlorofluorocarbon com!ounds (CCs) and water a!our are res!onsible for "lobal warmin . Je can reduce +lobal warmin" b followin" m ethod a) to minimise the use of automobiles.
b) !lant more trees to increase the "reen coer 3.
What is ean %$ the reen h use effect?
#n increasin" the concentration of C#2 in the atmos!here, it tra!s the earth ra diation and hence the tem!erature of the earth surface increases. This !henomenon is nown as +reen 3ouse eff ct. This results in meltin" of !olar ice ca!s and floodin" of low li n" areas. 6. Oone in t!e stratos"!ere is ro'u$e' #* t!e !el" o( ultraviolet ra'iations. I "rote$ts us (ro+ !ar+(ul ultraviolet ra'iations. a; 4rite e>uation (or t!e (or+a ion o( oone in stratos"!ere. #; E"lain 3it! $!e+i$al e>uati n t!e 'estru$tion o( oone #* $!loro(luro $ar#ons $ausin) oone !ole.
Ans6 a) #@one is formed in the u!!er str atos!here b the interaction of u radiation on d iox"en. #2(") sun li"ht #(") 9 #(") #(") 9 #2(") #(") b) In stratos!here, CCSs "et broe n down b _- radiations, releasin" chlorine free radical. C2Cl2(") u Cl (") 9 C2Cl(") The chlorine radical then react with o@o e to form chlorine monoxide radicals and mole ular ox"en. Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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Cl (") 9 #(") Cl# (") 9 #2(") =eaction of chlorine monoxide radical with atomic ox"en !roduces more chlorine radic ls. Cl# (") 9 #(") Cl (") 9 #2(") The chlorine radicals are continuousl r "enerated and cause the breadown of o@one. ". Suppose that $our teacher as s $ou to conduct a seinar on o
a) Jith the de!letion of o@o e laer, more _- radiation filters into tro!os!h re. _- radiations lead to a"ein" of sin, cataract, sunburn, sin cancer, illin" of man !hto!lantons, dama e to fish !roductiit etc. b) It has also been re!orted t hat !lant !roteins "et easil affected b _- radi tions which leads to the harmful mutation of cells. c)
It also increases ea!oration of surface water throu"h the stomata of the leaes and decreases the moisture content of the soil. Increase in _- radiations dama"e !aints and fibres, causin" them to fade faster.
. 4!at is +ean #* a$i' rain05 "lain t!e $auses an' !ar+(ul e((e$ts o( a$i' r in.
Jhen the !3 of the rain water dro!s below ., it is called acid rain. #xi es of nitro"en and sul!hur (e.". :# 2 and N#2) are mainl res!onsi le for acid rain. The harmful effects of acid rain re6 a) b) c) d) e)
N I . E V i L S S H
It is harmful for a"riculture, tree s and !lants. It causes res!irator ailments an d sin cancer in human bein"s and animals. It affects !lants and animal life in auatic ecosstem. It corrodes water !i!es resultin in the dissolution of hea metals into the drin in" water. Acid rain dama"es buildin"s and other structures made of stone or metal (e.". T e TaB $ahal).
. 4!at are t!e 'i((erent +eas res to re'u$e a$i' rain5 Acid rain can be reduce b the followin" methods6 a) =educe the use of automobiles. b) 'ncoura"e the use of natural "a instead of coal. c) Cataltic conerters must be us d in motor ehicles to reduce the emission of C and oxides of Nitro"en to the atmos!here. d) Acidit of the soil can be reduced b addin" !owdered limestone. e) Aware the !ublic about acid rai . G. T!ere are international stan'ar's re)ar'in) 'rin-in) 3ater. 4rite an* t!ree a+on) t!e+. The International :tandards for dri in" water are "ien below6 luoride6 or drinin" !ur!oses, water should contain fluoride u!to 1 !!m (!art !er million). 5ead6 The u!!er limit concentration of lead in drinin" water is about !!b (!a rts !er billion). :ul!hate6 5ess than !!m . Pollution o( 3ater ori)inates ainl* (ro+ !u+an a$tivities. a; 4!at 'o *ou +ean #* t!e ter+ PCB5 #; Ho3 'o $!e+i$al "ollutant $ause eutro"!i$ation5 $; Mention t!e a'verse e((e$ts o( !i)! (luori'e $on$entration in 'rin-in) 3at r.
Ans6 a) 7C* ? 7olchlorinated bi!henls (7ollution Control *oard) b) Chemical !ollutants cause 'utro!hication. ertili@ers contain !hos!hates an the !resence of !hos!hates in water increases the "rowth of al"ae. The increased amount of al"ae reduces the ox"en concentration in water. c) 'xcess fluoride is harmful to teeth and bones. 1. 4rite an* t3o 'i((eren$es #et3ee $lassi$al s+o) an' "!oto$!e+i$al s+o).
Classical smo" occurs in cool hu id climate. Chemicall it is a reducin" mixture. o it is called reducin" smo".
Anil Kumar K.L , GHSS Ashtamudi,Koll m[HSSLiVE.IN]
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