: Identification Reaction of Cation and Anion :1. To know know specia speciall reagent reagentss for each cation cation and anion in a group 2. To show identification reaction of cation and anion 3. To write the chemical reaction C. BASIC THEO THEORY RY : CATION A. TITL TITLE E B. PURPOSE
Cation analysis reuires a systematic approach. This is generally done in two ways! namely separation and identification. The separation is done "y dissol#ing a group cation out of the solution. Cation group precipitate separated from the solution "y centrifuge and the filtrate poured into another test tu"e. $olution which still contains contains most of the cation is dissol#e once more to form a new group of cations. If the group of cation that is dissol#e still contains some cations! so cations are then separated again into smaller groups of cations! and so on so that ultimately e%acer"ate the specific test for the cation. The type and concentration of the reactants and the p& ad'ustment is done to separate the cation into se#eral groups. (ualitati#e analysis is a method used for identification of ions or compounds in a sample. In many cases! ualitati#e analysis will also in#ol#e the separation of ions or compounds in a mi%ture. )%amples of ualitati#e tests would include ion precipitation reactions *solu"ility tests+ or chemical reacti#ity tests. The separation of ions is easily achie#ed "y taking ad#antage of their solu"ility properties &a#ing "ecome familiar with the characteristic reactions of cations! one may "e a"le a" le to identify an unknown material using simple chemical tests and separations. In this process! called inorganic ualitati#e analysis! one deals with the detection and identification of the elements that are present in a sample of material. ,reuently this is accomplished "y making an aueous solution of the sample and then determining which cations and anions are present on the "asis of chemical and physical properties. If a sample contains only a single cation! their identification is a fairly simple and straightforward process! although to distinguish "etween two cations *or anions+ that that ha#e ha#e simil similar ar chemica chemicall proper propertie tiess is not easy and in this this instan instance ce additio additional nal Analysis Cation And Anion
1
confirmatory tests are reuired. The detection of a particular ion in a sample that contains se#eral ions is somewhat more difficult! "ecause the presence o the other ions may interfere with the test. This pro"lem can "e circum#ented "y precipitating! there"y remo#ing! the distur"ing ions from solution prior to testing for the particular ion. The successful analysis of a mi%ture containing large num"er of ions centres upon the systematic separation of the ions into groups containing only a few ion. It is much simpler task to work with 2 or 3 ions than with 1- or more. ltimately! the sepa separa rati tion on of cati cations ons depen depends ds upon upon the the diff differ erenc encee in thei theirr tende tendenc ncie iess to form form precipitates! or to form comple% ions. /ne of the "est and well known separation scheme! outlined "elow! was first descri"ed "y R. ,resenius in 101! though in the course of time modifications were introduced. In this system cations are classified into fi#e groups on the "asis of their "eha#ior against some reagents! called groupreagents. y the systematic use of these reagents one can decide a"out the presence or a"sence of groups of cations! and can also separate these groups for further e%amination. The group reagents used for the classi classific ficati ation on of most most common common cation cationss are hydroch hydrochlor loric ic acid! acid! hydroge hydrogen n sulfid sulfide! e! ammonium sulfide! and ammonium car"onate. Classification is "ased on whether a cation reacts with these reagents "y the formation of precipitates or not. It can therefore "e said that classification of the most common cations is "ased on the differences of solu"ility of their chlorides! sulfides! and car"onates. The fi#e groups of cations and the characteristics of these groups are as follows:
Group 1 Cations of this group form precipitates with dilute hydrochloric acid. Ions
of this group are lead *II+! mercury *I+! and sil#er *I+. Rationale: $oftest acids react strongly enough with a "orderline "ase to precipitate in acid solution Group 2 The cations of this group do not react with hydrochloric acid! "ut form precipitates with hydrogen sulfide in dilute mineral acid medium. Ions of this group are mercury *II+! copper *II+! "ismuth *III+! cadmium *II+! tin*II+! tin*I4+! arsenic*III+! arsenic*4+! antimony*III+! and antimony*4+. The first four form the Analysis Cation And Anion
2
su"group 25a and the last si% the su"group 25". 6hile sulfides of cations in 7roup 25a are insolu"le in ammonium polysulfide! those of cations in 7roup 25" are solu"le. Rationale: $oft acids react with a #ery soft "ase.
Group 3
Cations of this group do not react either with dilute hydrochloric acid! or with hydrogen hydrogen sulfid sulfidee in dilute dilute minera minerall acid acid medium medium.. &owe#e &owe#err they they form form precipitates with ammonium sulfide in neutral or ammoniacal medium. Cations of this this grou group p are are iron iron *II+ *II+!! iron iron *III+! *III+! co"alt co"alt *II+! *II+! nickel nickel *II+! *II+! manganese manganese *II+! *II+! chromium *III+! aluminum *III+! and 8inc *II+. Rationale *1+: 9n$! i$! ,e$ as sulfides! i.e. "orderline acids "ind to a #ery soft "ase! when the p& is ad'usted so as to weaken the ;*/&2+nm< hydrated cation. Rationale *2+: ,e*/&+3! Cr*/&+3! Al*/&+3 precipitate "ecause these are hard acids reacting with the hard "ase /&. As acidic cations! they will tend to precipitate when the p& is eual to the p=a. These are all hard cations! and therefore prefer the hard "ase /&>
Group 4
Cations of this group do not react with the reagents of 7roups 1! 2! and 3. They form precipitates with ammonium car"onate in the presence of ammonium chloride in neutral medium. Cations of this group are calcium *II+! strontium *II+! and "arium *II+. Rationale: These are weakly acidic *ronsted definition+ cations. The car"onates are insolu"le "ecause of the fa#ora"le lattice energy when the weakly "asic car"onate ion reacts with these cations! since the cation and anion are "oth dou"ly charged and similar in si8e.
Group 5
Common cations! which do not react with reagents of the pre#ious groups! form form the last last group group of cation cations! s! which which includ includes es magnes magnesium ium*II *II+! +! lithium lithium*I+ *I+!! sodium*I+ sodium*I+!! potassium* potassium*I+! I+! and ammonium*I+ ammonium*I+ ions. Rationale: Rationale: These are weakly acidic *ronsted definition+ cations. The car"onates are insolu"le "ecause of the Analysis Cation And Anion
3
fa#ora"le lattice energy when the weakly "asic car"onate ion reacts with these cations! since the cation and anion are "oth dou"ly charged and similar in si8e.
ANION :
(ualitati#e analysis is a method used for identification of ions or compounds in a sample. In many cases! ualitati#e analysis will also in#ol#e the separation of ions or compounds in a mi%ture. )%amples of ualitati#e tests would include ion precipitation reactions *solu"ility tests+ or chemical reacti#ity tests. The separation of ions is easily achie#ed "y taking ad#antage of their solu"ility properties To facilitate the analysis process! it is often useful to put ions that react in similar ways and follow similar chemical reaction patterns into groups. ,or e%ample! it may "e useful to group ions "ased on their solu"ility properties. $ome anions such as halides and sulfates are insolu"le in lead containing solutions while remaining solu"le in iron or copper containing solutions. Therefore! anions can "e roughly classi classifie fied d into into groups groups accordi according ng to their their solu"i solu"ilit lity y in a parti particula cularr soluti solution. on. The react reactio ions ns used used to form form grou groups ps of anion anionss are are refe referr rred ed to in this this la" la" prot protoco ocoll as classification reactions. The indi#idual anions in each group are then separated and identified using different reactions often referred to as confirmatory reactions. &a#ing "ecome familiar familiar with the characteris characteristic tic reactions of anions! anions! one may "e a"le a" le to identify an unknown material using simple chemical tests and separations. In this process! called inorganic ualitati#e analysis! one deals with the detection and identification of the elements that are present in a sample of material. ,reuently this is accomplished "y making an aueous solution of the sample and then determining which anions and anions are present on the "asis of chemical and physical properties. If a sample contains only a single anion! their identification is a fairly simple and straightforward process! although to distinguish "etween two anions that ha#e similar chemical properties is not easy and in this instance additional confirmatory tests are
Analysis Cation And Anion
4
reuired. The detection of a particular ion in a sample that contains se#eral ions is somewhat more difficult! "ecause the presence o the other ions may interfere with the test. test. This This pro"le pro"lem m can "e circum circum#ent #ented ed "y precip precipit itati ating! ng! there" there"y y remo#i remo#ing! ng! the distur"ing ions from solution prior to testing for the particular ion. The successful analysis of a mi%ture containing large num"er of ions centres upon the systematic separation separation of the ions into groups containing containing only a few ion. It is much simpler simpler task to work with 2 or 3 ions than with 1- or more. ltimately! the separation of anions depends upon the difference in their tendencies to form precipitates! or to form comple% ions. The methods a#aila"le for the detection of anions are not as systematic as those which ha#e "een descri"ed a"o#e for cations. o really satisfactory scheme has yet "een proposed which permits the separation of the common anions into ma'or groups! and the su"seuent uneui#ocal separation of each group into its independent constituents? howe#er! it is possi"le to detect anions indi#idually in most cases! after perhaps a 12 stage separation. It is ad#antageous to remo#e all hea#y metals from the sample "y e%tracting the anions through "oiling with sodium car"onate solution? hea#y metal ions are precipitated out in the form of car"onates! while the anions remain in solution accompanied "y sodium ions. The following scheme of classification of anions has "een found to work well in practice? anions are di#ided into four groups on the "asis of their reactions with dilute hydrochloric acid and of the differences of solu"ility of their "arium and sil#er salts.
Analysis Cation And Anion
5
The four four groups groups of anions anions and the charac character terist istics ics of these these groups groups are as follows:
Group 1
4isi"le change! gas e#olution and5or formation of a precipitate! with dilute hydrochloric acid. Ions of this group are car"onate! silicate! sulfide! sulfite! and thiosulfate. The first group of anions to "e separated will "e those that precipitate in the presence of calcium ions! Ca<2. $ulfate ions! $/2! and car"onate ions! C/32! precipitate! that is they form a solid! when mi%ed with an aueous solution containing Ca2< ions. The net ionic euations representing the reactions occurring are shown "elow: Ca<2*a+ < $/2*a+
Ca$/*s+
)uation 1
Ca<2*a+ < C/32*a+ @ CaC/3*s+ )uation 2 A confirmatory reaction that distinguishes "etween sulfate ion and car"onate ion utili8es the fact that calcium car"onate will undergo a reaction with a strong acid to form form car"o car"on n dio% dio%id idee gas gas and wate waterr while while calc calciu ium m sulf sulfat atee will will not not *see *see euations 3 and +. CaC/3*s+ < 2&<*a+ @ Ca<2*a+ < C/2*g+ < &2/*l+
)uation 3
Ca$/*s+ < &<*a+ @ o Reaction *precipitate remains+
)uation
Analysis Cation And Anion
6
Group 2
The The anio anions ns of this this grou group p do not not reac reactt with with hydr hydroc ochl hlor oric ic acid! acid! "ut "ut form form precipitates with "arium ions in neutral medium. Ions of this group are sulfate! phosfate! fluoride! and "orate. 6hen mi%ed with dilute sulfuric acid! and heated! the nitrite ion! /2! forms red"rown nitrogen dio%ide gas and nitrate ion. This is a confirmatory reaction! since only one ion is in#ol#ed. 2/2*a+ @ /*a+ < /3*a+
)uation
2/*g+ *colorless+ < /2*g+ @ 2/2*g+ *red"rown+
)uation B
)uation is a simplified representation of a multistep process in#ol#ing hydrolysi hydrolysiss and autoredo% autoredo% reactions reactions of nitrite ion *that is! / 2 is acting as "oth the o%idi8ing agent and the reducing agent+. ote that car"onate ion could also "e listed in this group *gas forming anions+! since it does produce a gas! car"on dio%ide! in its reaction with acid. &owe#er! the presence of car"onate ion was "e confirmed earlier in 7roup I.
Group 3
Anions of this group do not react either with dilute hydrochloric acid! or with "arium ions in neutral medium. &owe#er! &o we#er! they form precipitates with sil#er ions in dilute nitric acid medium. medium. Anions of this group are chloride! "romide! "romide! iodide! iodide! and thiocyanate. recipitation is also the main reaction type in the classification of halides! "ut with a different precipitating agent than for 7roup I a"o#e. Cl! r ! and I ions! when mi%ed with an aueous solution containing Ag< ion! form precipitates that are insolu"le in water. As As opposed to other solid sil#er salts! sil#er halides h alides are also insolu insolu"le "le in stron strong g acid acid *nitri *nitricc acid acid will will "e used used here+. here+. Therefor Therefore! e! once the
Analysis Cation And Anion
7
precipitate is formed! it will not dissol#e on addition of acid. The Ag< ion solution used in this e%periment is aueous sil#er nitrate solution! the only sil#er salt that is solu"le in water. et ionic euations: Ag<*a+ < Cl*a+ @ AgCl*s+
)uation D
Ag<*a+ < r *a+ @ Agr *s+ *s+
)uation 0
Ag<*a+ < I*a+ @ AgI AgI*s+
)uation E
Confirmatory reactions that distinguish "etween the three halide ions and identify each are "ased on a redo% process. All three halides can act as reducing agents and in the process are o%idi8ed to their diatomic elemental forms. Their relati#e reducing strength is as follows: I Fr F Cl. 6hen coupled with a strong o%idi8ing agent such as aueous Cl2 *chlorine water+! "romide and iodide ions will undergo o%idation. If chloride reacts with chlorine it will produce chloride and chlorine. 6hile this may happen! it is easier to say that no reaction occurs Cl2*a+ *colorless+ < Cl *a+ *colorless+ @ o Reaction
)uation 1-
Cl2*a 2*a++ *colorless+ < r * a a+ *colorless+ @ r 2*a 2 *a++ *yellow to "rown + < Cl *a+
*colorless+ Cl2*a+ *color *colorles less+ s+ < I *colorless+
)uation 11 *a+
*color *colorles less+ s+ @ I2*a+ *yel *yello low w to "row "rown+ n+ < Cl*a+ )uation 12
If Cl ion is present in the solution! without any other halide! the chlorine water will remain colorless. Therefore! this test #erifies the presence of Cl ion only if the classification test produced a sil#er precipitate that did not dissol#e in acid. After addition of colorless chlorine water to a colorless solution of either "romide or iodide! the solution will change color to yellow"rown! since elemental iodine and "romine impart such color to water. This test! howe#er! does not distinguish "etween the two ions. /ne more step is necessary. It is not a reaction! "ut a physical process of e%traction with he%ane of the solution o"tained Analysis Cation And Anion
8
upon addition of chlorine water. wa ter. A small #olume of he%ane is added ad ded to the yellow "rown halide solution. A pink or purple he%ane layer *the top layer+ after e%traction indicates that the initial solution contained I ion. A yellow to "rown orange he%ane layer indicates that the initial solution contained r ion. The actual shade of the he%ane layer depends on the concentration of the halogen *a higher concentration of the halogen produces a darker shade+.
Group 4
Common anions! which do not react with reagents of the pre#ious groups! form the last group of anions! which includes nitrite! nitrate and chlorate ions. itrate ion does not directly produce any precipitates *remem"er the solu"ility rulesG rulesG++ nor does does it produc producee any gaseous gaseous products products in an acidic acidic en#iron en#ironmen ment. t. &owe#e &owe#er! r! upon reduct reduction ion "y ,e2< ,e2< ion it forms forms a charac character terist istic ic "rown "rown gas! gas! nitrogen dio%ide. As with nitrite! the reaction is considered a confirmatory one. The euations for the reactions in#ol#ed are as follows: /3*a+ < &<*a+ < 3,e2<*a+ @ /*a+ < 3,e3<*a+ < 2&2/*l+ )uation 13 2/*g+ *colorless+ < /2*g+ @ 2/2*g+ *red"rown+
)uation 1
A specific test reagent! ideally! possesses a specific reaction with each type of anion. The reagent might react with one anion to pro#ide a distinguishing product! "ut not no t with the other anions in the mi%ture. The color c olor of precipitate formed and the reaction of the precipitate formed with dilute acid or identity of gas li"erated gi#es us definiti#e proof of the unknown anion an ion in the solution.
Analysis Cation And Anion
9
There are three main solution tests and these are also confirmatory tests for specific anions: Test reagents
$pecific Anions Identified
$il#er nitrate solution followed "y dilute nitric acid
Chloride! ClIodide! ICar"onate! C/32-
arium nitrate solution followed "y $ulfate! $/2dilute nitric acid or $ulfite! $/32arium chloride solution followed Car"onate! C/32 "y dilute hydrochloric acid.
Head*II+ nitrate solution
Chloride! ClIodide! I$ulfate! $/2Car"onate! C/32-
Addition of a/&! aluminum foil 5 itrate! /3 powder or e#ardaJs alloy. alloy. &eat
The principles that are employed in the identification of cations can also "e applied to the analysis of anions. The ualitati#e detection of anions in a sample depends on the distincti#e solu"ility properties of particular salts of the ions and specific chemical reactions that are *ideally+ uniue to a particular ion.
Analysis Cation And Anion
10
D.
TOOLS AND MATERIALS . C!"o#
:
;aterials
Tools
$ample
eaker 7lass
Auades
Test Tu"e
&Cl B ;
Rack
&2/2 3K 3K
Tripot
&Cl 2 ;
urner
&Cl 2 ;
$patula
&/&
=assa
Ammonium /%alate
Clamp
$. A#"o# M!%r"&'
Too&'
nknown $olution
Test tu"e
a2C/3 co concentrate
urner
Ag/3
Tripot
=assa Clamp
Analysis Cation And Anion
11
E.
PROCEDURE . G%# G%#%r %r&& Pro(%)ur Pro(%)ur%% o* C!"o# C!"o#
Analysis Cation And Anion
12
$. A#&+'" A#&+'"'' Pro( Pro(%)ur %)ur%% o* o* C!"o C!"o# # C2, Sampl
Analyt
-
Thinned with auades
-
Added drops of solution into test tu"e Added drops of water Added 2 drops of &Cl B ; $tirred 6ashed 6a shed su"stances that stick on the wall with water
Filtrate for
-
-
Added drops of &Cl 2 ;
;i%ed it well Added 1 drops of &/&! drop "y drop $tirred
Analyte Contain of
-
Added B drops of &2/2 3K
Added 2 drops of &Cl 2 ; oiled until reach #olume 12 drops Cooled dawn Added B drops of &Cl B ; )#aporated
Analyte for
-
-
-
Added 2 drops of &/& Added 2 drops of Ammonium /%alate
White Precipitate
Analysis Cation And Anion
13
(. A#& A#&+'" +'"'' Pro( Pro(%) %)ur ur%% o* A#"o A#"o# # C& -
1. ;aki ;aking ng repar reparat atio ion n $olu $oluti tion on
U##o#
&eated wi with a2C/3 concentrate
reci itate
,iltrate
sed for ne%t analysis *supply
2. ro#i ro#ing ng Ther ThereL eLss Cl reparation $olution
Added Ag/3 6hite recipitate Cl e%ist
-Added NH3 issol#e
Analysis Cation And Anion
14
/.
E0PERIMENT RESULT . No.
C!"o# C2, Pro(%)ur% o* Ep%r"%#!
Ep%r"%#! R%'u&!
Analysis Cation And Anion
H+po!%'"' R%(!"o#
Co#(&u'"o#
15
B%*or%: Sampl
$ample: colorless Thinned with auades Analyt
-
-
Adde d drops of solution into test tu"e Added drops of water Added 2 drops of &Cl B ; $tirred 6ashed 6a shed su"stances that stick on the wall with water
Filtrate for
-
Added B drops of &2/2 3K Added 2 drops of &Cl 2 ; oiled until reach #olume 12 drops Cooled dawn Added B drops of &Cl B ; )#aporated
Analyte for
-
Added drops of &Cl 2 ; - ;i%ed it well - Added 1 drops of &/&! drop "y drop - $tirred Analyte Contain of
Analysis Cation And Anion
6a 6ater ter : colorless colorle ss &Cl
: colorless
&2/2
: colorless
&Cl : colorless &/& : colorless Ammonium /%alate *&+2$ : yellow
A*!%r:
$ample < auades: colorless solution *sample solution+ $ample solution < water: colorless solution $ample solution < water < &Cl: colorless solution *filtrate for procedure II+
,irst! we made a hypo thesis that the sample which is gi#en contain of cation ;g2
$eparation of calcium with other cation "ased on the solu"ility of CaC2/ salt which canLt dissol#e on the water! hence the other cation is easy to dissol#e. If thereLs white precipitate in calcium! CaC2/ will "e form when adding *&+2C2/. $olution made in "ase condition to pre#ent the solu"ility of o%alate salt.
Ca*/&+2*a+ < C/2*g+
Ca*/&+2*a+ <
,iltrate 2 < &2/2: colorless solution
2&Cl*a+@
,iltrate 2 < &2/2 < &Cl: colorless solution
2&2/
After After "oiled and cooled dawn and drop &Cl and
Ca2< <
CaCl2*a+<
*C//+22 @
16
-
Added 2 drops of &/& - Added 2 drops of Ammonium /%alate
e#aporated: colorless Ca*C//+2 M solution Ca2< < C2/ CaC2/*s+
White Precipitate
Analysis Cation And Anion
17
$. A#"o# C&No
Pro(%)ur% o* o* E E p%r"%#!
Ep%r"%#! R%'u&!
H+po! o!%'"' '"' R% R%((!"o# "o#
Co#(& #(&u'"o '"o#
.
;aking reparation
B%*or%: - nknown solution: colorless a2C/3 concentrate: colorless Ag/3: colorless A*!%r: nknown solution < a2C/3: colorless filtrate and white precipitate $upply $olution < Ag/3: 6hite precipitate
nknown solution
There is white precipitate after adding Ag/3 so the anion of Cl is pro#en.
U##o#
$olution
&eated with a2C/3 Pr% Pr%(" "!! "!!%%concentrate /"&!r!%
2.
sed for ne%t analysis *supply solution+
Pro"#6 Pro "#6 T%r%7' T %r%7' C& C &-
re aratio aration n $oluti $olution on
Na2CO3 + CaCl2 → CaCO3 + 2NaCl Na2CO3 + 2 AgNO3 → 2 NaNO3 + Ag2CO3 NaCl + AgNO3 → AgCl ↓ !ite + NaNO3 AgCl ↓+ 2NH3 → "Ag#NH3$2%+ + Cl
6hite recipitate Cl e%ist -Added NH3 issol#e
Analysis Cation And Anion
18
G. ANALY ANALYSIS AND DISCUSSION DISCUSSION ANALYSIS O/ CATION
In this e%periment! the sample is colorless co lorless and the shape is like 'elly. sample is dissol#ed in a test tu"e "y using auades! this is done to simplify the analysis of anions and cations. cations. Then the samples were dissol#ed dissol#ed according with the procedures procedures analy8ed cation analysis in general. The first sample of B ; &Cl added three drops! precipitate containing group 1! the filtrate containing group 2! 3! or after the &2$ gas flowed and added with &CH. recipitation in the form group 2 and the filtrate containing group 3! or . Added *&+ 2$ precipitate containing group 3 and filtrate containing group or . Added *&+2C/3 precipitate containing group and filtrate containing group . ,irst we suppose that the samples containing cations ;g2
Analysis Cation And Anion
19
o%alate compounds. The function of ammonium o%alate for precipitate Ca. Therefore! we conclude that the sample contains cations Ca2< Ca2< < *C//+22 @ Ca*C//+2 M Ca2< < C2/ CaC2/*s+ ANALYSIS O/ ANION
Analyte is colorless and the shape is like 'elly. To know there is anion on analyte! the first step that we ha#e done is adding saturated a2C/3 to the reaction tu"e which contain of analyte so it formed colorless solution. The purpose of adding a2C/3 is to dissol#e the anion on the analyte ! with analyte CaCl 2 *Ca is our cation+ that ha#e "een found so the euation that will "e happen is : a2C/3 < CaCl2 @ CaC/3 < 2aCl The ne%t step is heating the reaction tu"e! it purpose to faster the reaction that occur or in other case it can gi#e the acti#ation energy to the solution! so the reaction which didnLt take place in the "eginning "ecause less of acti#ation energy! through of heating the reaction can "e occur. The third step is separation "etween precipitate and filtrate! it purpose to remo#e the other su"stance which may "e react with reagent to "e added later. And the fourth steps is adding Ag/3 and filtrate! it purpose to difference "etween Cl and r. a2C/3 < 2 Ag/3 @ 2 a/3 < Ag2C/3 CO32- ion is precipitated when ionic displacement occurs .. In this e%periment Cl ion would "e formed white precipitate and r ion would "e formed yellow precipitate. aCl < Ag/3 @ AgCl M white < a/3 The last last step is dissol#e dissol#e the precip precipitate itate into into &3 it purpose to keep the possi"ility of a su"stance that
formed isnLt AgCl! "ecause AgC has white
precipitate too! so that if the su"stance is reacted with &3! AgCl will react while while AgC not react! so that when the precipitate dissol#ed in & 3 it can "e concluded that of the analyte anion is Cl. The reaction is: AgCl M< 2&3 @ NAg*&3+2O< < Cl
Analysis Cation And Anion
20
H.
CONCLUSION
ased on e%periment that we ha#e done! we can conclude that : 1. Cation Cation that that contain contain in our analyte analyte is Ca2< 2. Anion that contain contain in our analyte analyte is Cl 3. Compound Compound that our o"ser#e o"ser#e is CaCl CaCl2
I.
ANS8ER AND 9UESTION
1. Write the general reaction for each group!
&'o() * ,+ + Cl- ↔ ,Cl ↓ ,+ + 2Cl- ↔ ,Cl2 ↓ it! ,+ As+ dan Hg22+ . ,2+ /+ &'o() ** ,2+ + 2- ↔ , ↓ 3,3+ + 22- ↔ ,23 ↓ ,4+ + 22- ↔ ,2 ↓ it! ,2+ C(2+ Cd2+ /2+ . ,3+ 3 As3+ 3+ . ,4+ n4+ !e olo' o sedient de)ends on ea! ati ation on ie Hg Hg i23 C( t!e la Cd As23 n2 yello and 23 25 is 'ed !e )'ei)itation a''ied o(t in aid sol(tion it! t!e atos)!e'e #H2 ontaining dil(te HCl$ &'o() *** M3+ + NH3 + H2O
M(OH)3(s) + :& 1
+
,2+ + 2OH- ↔ ,#OH$ 2 it! ,3+ :e3+ Al3+ C'3+ . ,2+ ,n2+ &'o() &'o() ***A !e olo' o t!e )'ei)ita )'ei)itate te de)ends on t!e 'es)eti;e 'es)eti;e ations naely Fe(OH)3, Al(OH)3 !i! is !ite Cr(OH)3 g'eenis! g'ay &'o( &'o() ) *** *** !e !e olo olo'' o t!e t!e )'e )'ei) i)it itat ate e de)e de)end nds s on ea! ea! ation t!e N* Co
Analysis Cation And Anion
21
la la ,N olo' olo' )in )in and !ite !ite
,2+ + 2- ↔ , ↓ it! ,2+
&'o() =
,2+ + CO32- ↔ ,CO3 >it! ,2+ a2+ '2+ Ca2+
*n g'o() = t!e'e is no oon 'eagents so t!at a s)eial 'eation test (sed to identiy d'y ions ?'y test aong ot!e's test t!e in@atale t(e staining test @ae test and so o't!
Why ox oxid idiz izer er used used in the the anal analys ysis is of cati cation ons s in the the 2. Why system H2S is H 22 or romine" and instead of H#$% OidiBe' (sed in t!e analysis o ations in t!e syste H2 is H2O2 o' 'oine ea(se H2O2 is ;olatile !en added to ate' in o'de' to get salt de)osits de)osits o s(lde s(lde H 2 And instead o (sing an oidiBing aid HNO3 ea(se all t!e salt (st e 'eo; eo;ed ed so t!at t!at t!e t!e s( s(l lte te de)o de)osi sits ts ill ill not not e o' o'ed ed ea ea(s (se e t!e t!e H2 gas is )ass )assed ed in t!e t!e anal analy yte in ai aidi di onditions 3. Ho& do &e 'no& that H2S" H 22" or (r2 is not contained
in the solution% o o dete'ine dete'ine t!e H2 is not )'esent in t!e sol(tion e an oiled to 'eo;e t!e H 2 and to no t!at t!e H2 as gone ent'y t!e lte' )a)e' to t!e /Daetate t!an la) t!e
Analysis Cation And Anion
22
lt'ate )a)e' ate' t!at di'eted to t!e E'leneye' o(t! i t!e lte' )a)e' as la it signiy t!at H 2 still eist (t i t!e lt'ate lt'ate )a)e' )a)e' didnFt !ange !ange into la la it signiy signiy t!at t!e t!e H2 as gone o o dete'ine dete'ine H2O2 as as not not )'es )'esen entt in t!e t!e sol( sol(ti tion on di))ed t!e lte' )a)e' into HCl t!en aed it! t!e !ose !oles !i! a'e dist'i(ted to H 2O2 * t!e'eFs t!e'eFs no la s)ot in t!e lte' )a)e' it s!o t!at t!e'eFs no H2O2 o o no '2 as not )'esent in t!e sol(tion t!'o(g! e;a)o'ate t!e sol(tion oe oing o(t )laed on a et sta'! )a)e' * t!e et sta'! )a)e' eoe 'eddis!-o'ange t!e '2 is still t!e'e (t i t!e o'ange '2 is not t!e'e 4. 8+ !o )%!%r )%!%r"#% "#% !% !% pr%'%# pr%'%#(% (% o* NH 4 , (!"o#' 'ou&) $% u'%) "!7' #&+!% )"r%(!&+
ecause the reagent that we use to analyse the cathion of group I until group I4 contain &
Ho "' "' !% 6%#%r 6%#%r&& r%(!"o r%(!"o# # !o !% " "#6 #6 o* !% !% 'o&u!"o 'o&u!"o# # pr%pr pr%pr!"o !"o# # !o )%!%r"#% !% pr%'%#(% o* #"o# a2C/3 < 2&P @2aP < &2C/3
;. Pr%("p"!!"o# Pr%("p"!!"o# o* Su&*")% Su&*")% '&! o# !% #&+'"#6 #&+'"#6 (!"o#' (!"o#' o* 6roup 6roup II #) 6roup 6roup IIIB )o "# !% )"**%r%#(% (o#)"!"o# o* 'o&u!"o#. Ep&"# ecause in group II! the precipitation of the salt sulfide reacted under acidic
conditions! ie in &2$containing dilute &Cl. This is "ecause the filtrate which used to get the precipitate of salt sulfide from group I filtrate which contaion dilute dilute &Cl. &Cl. In group group III ! precip precipita itatio tion n of salts salts sulfid sulfidee reacte reacted d under under "ase "ase condition condition ie in &2$containing solution of &3 and &Cl. This is "ecause the filtrate which is used to get the precipitate of salt sulfide from the filtrate of group III A! which still contains & 3 and &Cl. <. 8+ "' !% pr%("p"!!" pr%("p"!!"o# o# o* 6roup I= u'! u'! $% "# !% $'% prop%r!" prop%r!"%' %'
Analysis Cation And Anion
23
The deposition of group I4 had under "ase properties "ecause the ammonium ! &/&! can pre#ent the loss of acids which #olatile so it will produce car"onate salts deri#ed from a solution of ammonium car"onate.
Analysis Cation And Anion
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>. RE/ERENCE
http:55www.inc."me.hu5en5su"'ects5inchem5silla"us512E1.pdf Accessed Accessed on ;onday! ecem"er 2nd 2-13 at 1:- http:55classes.uleth.ca52-12-15chem2---15BQ2-12K2-2---)%pt1Q(ual1B3.pdf Accessed on ;onday! ecem"er 2nd 2-13 at 1:30 http:55www2.ucds".on.ca5tiss5stretton5chem35la"Q2QintroQaQtheory.html Accessed http:55www2.ucds".on.ca5tiss5stretton5chem35la"Q2QintroQaQtheory.html Accessed on ;onday! ecem"er 2nd 2-13 at 1B:1 http:55chemisttry."logspot.com52-135-15analisakualitatifreaksiidentifikasi.html http:55chemisttry."logspot.com52-135-15analisakualitatifreaksi identifikasi.html Accessed on ;onday! ecem"er 2nd 2-13 at 1D: http:55www.crescent.edu.sg5cre8la"56e"pages5AnionHa";anual-1.htm http:55www.crescent.edu.sg5cre8la"56 e"pages5AnionHa";anual-1.htm Accessed on nd ;onday! ecem"er 2 2-13 at 1D:0 http:55www.inc."me.hu5en5su"'ects5inchem5silla"us512E1.pdf Accessed Accessed on ;onday! ecem"er 2nd 2-13 at 1:- http:55sunny.moorparkcollege.edu5chemistry5chemistryQ1Qla"s5e%perimentQtwel#e. pdf Accessed on ;onday! ecem"er 2nd 2-13 at 10:-1 http:55www.slccscience.org5chem5la"s5chem1225122e%periment-D.pdf Accessed on ;onday! ecem"er 2nd 2-13 at 10:1 $#ela! 7. 1E0. 4/7)H uku Teks Analisis Analisis Anorganik =ualitatif ;akro dan $emimakro. )disi ke . Sakarta: T. &a#ery Indah. Achmad! &iskia. 2-12. =imia Analitik =ualitatif. andung:T. Citra Aditya akti. Tim.2-13.anduan raktikum =imia Analitik I asarasar =imia Analitik. Analitik. $ura"aya:Surusan =imia ,;IA )$A
Analysis Cation And Anion
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ATTACHMENT PICTURE
E0PLANATION U#o# 'o&u!"o# ?(&%r &"% 6%&@
U##o# 'o&u!"o# (o#!"# (!"o# o* C ?CC2O4@
Sp&% o* #"o# 'o&u!"o#
Analysis Cation And Anion
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8"!% 8 "!% pr%( pr%("p "p"! "!!% !% 'o# 'o# #"o# #"o# o* C&-
Analysis Cation And Anion
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