Chapter 1 Keys to the Study of Chemistry
Chapter 1 Keys to the Study of Chemistry 1. Which one of the following is is a "substance" in the sense sense of the word as used used in your textbook? ! air ! tap water C! sea water #! water $! toothpaste ns% # &. Select the best best statem statement. ent. ! 'hysic 'hysical al chang changes es may may be be re(er re(ersed sed by chan changin ging g the the temp tempera eratur ture. e. ! 'hysic 'hysical al chang changes es alte alterr the the compos composit ition ion of of the the subst substance ancess in(ol in(ol(ed (ed.. C! 'hysic 'hysical al proper properti ties es are not not (alid (alid charact characteri eristi stics cs for iden identif tifyi ying ng a substan substance. ce. #! 'hysi 'hysical cal pro prope pert rtie iess are mos mostl tly y exten extensi si(e (e in natu nature re.. $! 'hysic 'hysical al changes changes are usu usuall ally y acco accompa mpanie nied d by by chem chemica icall chang changes. es. ns% ). Select the best best statem statement. ent. ! Chemi Chemical cal change changess pro(id pro(idee the only only (alid (alid basi basiss for ident identifi ificat cation ion of of a substa substance. nce. ! Chemi Chemical cal change changess are easi easily ly re(er re(ersed sed by alte alterin ring g the temp tempera eratur turee of the syst system. em. C! Chemi Chemical cal changes changes alwa always ys produc producee substan substances ces diffe differen rentt from the the start starting ing mater material ials. s. #! Chemi Chemical cal change changess are are associ associate ated d primar primarily ily wit with h extens extensi(e i(e prop propert erties ies.. $! Chemi Chemical cal change changess are are accomp accompanie anied d by change changess in the the total total mass mass of the the subst substanc ances es in(ol(ed. ns% C *. Which of the the following following is a chemica chemicall change? ! boiling of water #! ! melting wax $! C! broi broili ling ng a stea steak k on a gri grill ns% C
condensing water (apor into rainfall car(ing a piece of wood
+. Water (apor (apor is less less dense dense than ice because because ! mo mole lecul cules es in in the the gas gas phas phasee are are in con const stan antt moti motion on.. ! molecul molecules es in in the the gas gas phase phase ha(e ha(e more more potent potential ial ener energy gy than than in in soli solids. ds. C! molecul molecules es in in the the gas gas phase phase ha(e more more kinet kinetic ic ener energy gy than than in soli solids. ds. #! gase gaseou ouss m mol olec ecul ules es ha(e ha(e less less mass mass.. $! molecul molecules es in in the the gas gas phase phase ha(e ha(e more more space space betwe between en them them than than in in solid solids. s. ns% $ ,. #uring the swing swing of a frictionless frictionless pendulum- what energy forms! remain constant? ! kinetic en energy on only ! potential energy only C! both both kin kinet etic ic ene energ rgy y and and pote potent ntia iall ener energy gy #! kine kineti ticc plus plus pote potent ntia iall ener energy gy $! /one /one of thes thesee for forms ms rema remain inss con const stan ant. t. ns% #
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Chapter 1 Keys to the Study of Chemistry
0. Which of the following acti(ities is not a part of good science? ! proposing a theory #! designing experiments ! de(eloping a hypothesis $! indulging in speculation C! making uantitati(e obser(ations ns% $ 2. 3he distance between carbon atoms in ethylene is 1)* picometers. Which of the following expresses that distance in meters? ! 1.)* × 1451) m #! 1.)* × 1450 m ! 1.)* × 1451& m $! 1.)* × 145, m C! 1.)* × 14514 m ns% C 6. 3he a(erage distance from $arth to the Sun is 1+4 megameters. What is that distance in meters? ! 1.+ × 142 m #! 1.+ × 14) m ! 1.+ × 14, m $! 1.+ × 145, m C! 1.+ × 14+ m ns% 14. 3he mass of a sample is ++4 milligrams. Which of the following expresses that mass in kilograms? ! +.+ × 142 kg #! +.+ × 145, kg ! +.+ × 14+ kg $! +.+ × 1451 kg C! +.+ × 145* kg ns% C 11. dose of medication was prescribed to be )+ microliters. Which of the following expresses that (olume in centiliters? ! ).+ × 14+ c7 #! ).+ × 145* c7 ! ).+ × 14* c7 $! ).+ × 145) c7 C! ).+ c7 ns% $ 1&. Which of the following represents the largest (olume? ! 14-444 87 ! 1444 p7 C! 144 m7 #! 14 n7 ns% C
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$! 14 cm)
Chapter 1 Keys to the Study of Chemistry
1). 9ou prepare 1444. m7 of tea and transfer it to a 1.44 uart pitcher for storage. Which of the following statements is true? ! 3he pitcher will be filled to 144: of its capacity with no tea spilled. ! 3he pitcher will be filled to about 6+: of its capacity. C! 3he pitcher will be filled to about +4: of its capacity. #! 3he pitcher will be completely filled and a small amount of tea will o(erflow. $! 3he pitcher will be completely filled and most of the tea will o(erflow. ns% # 1*. ;n an a(erage year the merican chemical industry produces more than 6.+ million metric tons of sodium carbonate. <(er half of this is used in the manufacture of glass while another third is used in the production of detergents and other chemicals. =ow many pounds of sodium carbonate are produced annually? ! &.1 × 1414 lb #! &.& × 14, lb ! *.) × 146 lb $! &.1 × 14* lb C! 1.1 × 140 lb ns% 1+. large pi>>a has a diameter of 1+ inches. $xpress this diameter in centimeters. ! )2 cm ! &* cm C! 12 cm #! 6.) cm $! +.6 cm ns% 1,. 3he a(erage distance between the $arth and the oon is &*4-444 miles. $xpress this distance in kilometers. ! ,.1 × 14+ km #! 1.+ × 14+ km ! +.) × 14+ km $! 6.* × 14* km C! ).6 × l4+ km ns% C 10. 3he area of a 1+5inch pi>>a is 10,.0 in&. $xpress this area in suare centimeters. ! 11*4. cm& ! **2.2 cm& C! 6,.2 cm& #! ,6.+0 cm& $! &0.)6 cm& ns% 12. 3he speed needed to escape the pull of $arth@s gra(ity is 11.) kmAs. What is this speed in miAh? ! ,+-+44 miAh #! 1-464 miAh ! &+-)44 miAh $! +.4& × 145) miAh C! 12-&44 miAh ns%
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Chapter 1 Keys to the Study of Chemistry
16. 3he density of mercury- the only metal to exist as a liuid at room temperature- is 1)., gAcm). What is that density in pounds per cubic inch? ! 2*6 lbAin) #! 4.*61 lbAin) ! *61 lbAin) $! 1.2) × 145) lbAin) C! )0, lbAin) ns% # &4. Bi(en that 1 inch &.+* cm- 1 cm) is eual to ! 1,.* in) ! ,.*+ in) C! 4.)6* in) #! 4.1++ in) ns% $
$! 4.4,14 in)
&1. t a pressure of one billionth 1456! of atmospheric pressure- there are about &.0 × 1414 molecules in one cubic centimeter of a gas. =ow many molecules is this per cubic meter? ! &.0 × 141, ! &.0 × 141* C! &.0 × 141& #! &.0 × 142 $! &.0 × 14* ns% &&. ;f the price of gold at the morning fixing in 7ondon was D+)14 per lb- what would a kilogram of gold ha(e cost in E pounds!? ssume an exchange rate of D1.44 E4.+*+! ! E1)14 ! E)+14 C! E,)04 #! E14*44 $! E10144 ns% C &). Which of the following is not an S.;. base unit? ! meter ! ampere C! second #! gram ns% # &*. 3he S.;. base unit of mass is ! mg ! g C! kg #! metric ton ns% C &+. 3he S.;. prefix mega5 ! means ! 145, ! 145) C! 14) #! 14, ns% #
$! kel(in
$! lb
$! 146
&,. 3he S.;. unit of speed (elocity! is ! kmAh ! kmAs C! mAh #! mAs ns% #
$! none of these choices is correct
&0. Which of the following is an extensi(e property of oxygen? ! boiling point #! density ! temperature $! mass C! a(erage kinetic energy of molecules ns% $
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Chapter 1 Keys to the Study of Chemistry
&2. flask has a mass of 02.&) g when empty and +6).,) g when filled with water. When the same flask is filled with concentrated sulfuric acid- = &S<*- its mass is 14&,.+0 g. What is the density of concentrated sulfuric acid? ssume water has a density of 1.44 gAcm) at the temperature of the measurement.! ! 1.66& gAcm) #! 1.+62 gAcm) ! 1.2*4 gAcm) $! 4.+*) gAcm) C! 1.0&6 gAcm) ns% &6. 3alc is a mineral that has low conducti(ity for heat and electricity and that is not attacked by acid. ;t is used as talcum powder and face powder. sample of talc weighs )+.60 g in air and 1).,+ g in mineral oil d 1.0+ gAcm)!. What is the density of talc? ! *.,1 gAcm) ! &.2& gAcm) C! &.,) gAcm) #! &.** gAcm) $! 1.,1 gAcm) ns% )4. cetone- which is used as a sol(ent and as a reactant in the manufacture of 'lexiglasF boils at +,.1GC. What is the boiling point in degrees Hahrenheit? ! 1+6GH ! 1))GH C! 141GH #! ,6.4GH $! *).*GH ns% )1. ;sopropyl alcohol- commonly known as rubbing alcohol- boils at 2&.*GC. What is the boiling point in kel(ins? ! )20., K ! )++., K C! )&)., K #! 164.2 K $! 5164.2 K ns% )&. cetic acid boils at &**.&GH. What is its boiling point in degrees Celsius? ! )2&.4GC ! 1,0.0GC C! 1+).*GC #! 110.6GC $! 14).0GC ns% # )). Select the answer that expresses the result of this calculation with the correct number of significant figures.
! 1).)+,2 ns% $
! 1).)+0
C! 1).),
#! 1).*
$! 1)
)*. Select the answer that expresses the result of this calculation with the correct number of significant figures and with correct units. ! ! C! ns%
14+.& gAcm) 14+.& gAcm& 14+.& gAcm C
#! $!
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0&.1) gAcm& 0&.1) gAcm
Chapter 1 Keys to the Study of Chemistry
)+. Which measurement is expressed to * significant figures? ! 4.44*&) kg ! &*.4*6 cm C! 1)44 K #! 2&-)4, m ns% $ ),. $xpress 6,-)*& m using & significant figures. ! 6.,4 × 14* m #! * ! 6., × 14 m $! 5* C! 6.,4 × 14 m ns%
$! ,&.*4 g
6., × 145* m 6,-444. m
)0. Select the answer with the correct number of decimal places for the following sum% ! ! C! ns%
&,6.412,4 cm &,6.412, cm &,6.416 cm $
#! $!
&,6.4& cm &,6.4 cm
)2. 3he appropriate number of significant figures in the result of 1+.&)* × 1+.&42 is ! & ! ) C! * #! + $! , ns% # )6. 3he appropriate number of significant figures in the result of 1+.&)* 5 1+.&42 is ! 1 ! & C! ) #! * $! + ns% *4. 3he result of ).2,&1 × 1.+,)4! 5 +.62 is properly written as ! 4.4, ! 4.4+, C! 4.4+,+ #! 4.4+,*, $! 4.4+,*,& ns% *1. s chief chemist at Superior nalytical 'roducts S'! you must design an experiment to determine the density of an unknown liuid to three )! significant figures. 3he density is of the order of 1 gAcm ). 9ou ha(e approximately 0 m7 of the liuid and only graduated cylinders and balances are a(ailable for your use. Which of the following combinations of euipment will allow you to meet but not exceed your goal? ! Braduated cylinder with I4.1 m7 uncertaintyJ balance with I4.1 g uncertainty ! Braduated cylinder with I4.41 m7 uncertaintyJ balance with I4.1 g uncertainty C! Braduated cylinder with I4.41 m7 uncertaintyJ balance with I4.41 g uncertainty #! Braduated cylinder with I4.441 m7 uncertaintyJ balance with I4.441 g uncertainty $! Braduated cylinder with I4.1 m7 uncertaintyJ balance with I4.441 g uncertainty ns% C
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Chapter 1 Keys to the Study of Chemistry
*&. ud /. Chemist must determine the density of a mineral sample. =is four trials yield densities of *.00 gAcm)- *.,0 gAcm)- *.,6 gAcm)- and *.21 gAcm). ;ndependent studies found the correct density to be *.0+ gAcm). Which of the following statements represents the best analysis of the data? ! ud@s results ha(e much greater accuracy than precision. ! ud@s results ha(e much greater precision than accuracy. C! ud@s results ha(e high accuracy and high precision. #! ud@s results ha(e low accuracy and low precision. $! ud@s euipment is faulty. ns% *). s part of an experiment to determine the density of a new plastic de(eloped in her laboratory- Sara nn #ippity measures the (olume of a solid sample. =er four trials yield (olumes of 1&.)0 cm)- 1&.*1 cm)- 1&.)6 cm)- and 1&.)2 cm). easurements of other scientists in the lab gi(e an a(erage (olume of 1&.*6 cm). Which of the following statements represents the best analysis of the data? ! Sara@s results ha(e low precision and high accuracy. ! Sara@s results ha(e high precision and high accuracy. C! Sara@s results ha(e greater precision than accuracy. #! Sara@s results ha(e greater accuracy than precision. $! Sara has been using a faulty instrument to measure the (olume. ns% C **. Which of the following correctly expresses +&-4)4.& m in scientific notation? ! +.&4)4& × 14* m #! +.&4 × 14* m ! +.&4)4& × 14+ m $! +.& × 14* m C! +.&4) × 14* m ns% *+. Which of the following correctly expresses 4.44444061) g in scientific notation? ! 0.61) × 14, g #! 0.61) × 145, g ! 0.61) × 14+ g $! 0.61) × 1456 g C! 0.61) × 145+ g ns% # *,. Bi(e an example of a physical property and a chemical property of each of the following% a. oxygen gas b. octane c. copper ns% nswers could all be the same- but some possibilities are a. boiling point- reaction with sodium b. boiling point- reaction with oxygen c. electrical conducti(ity- reaction with nitric acid
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Chapter 1 Keys to the Study of Chemistry
*0. riefly explain the relationship between hypothesis and experiment in the scientific method. ns% hypothesis should be capable of leading to a prediction which is testable by experiment. ;f the experimental result differs from the prediction- the hypothesis should be modified. *2. Calculate to three significant figures! the numerical part of the con(ersion factors needed to carry out the following unit con(ersions% a. density in gAcm) to kgAm) b. speed in miAh to ftAs c. area in km& to mi& d. area in km& to cm& e. massAarea of aluminum foil in mgAcm& to gAm& f. number of gas molecules per unit (olume from Am ) to Aft) g. number of bacteria per unit area on a microscope slide from Amm& to Ain& ns% a. 14) exactly! b. 1.*0 c. 4.)2, d. 1414 exactly! e. 14 exactly! f. 4.4&2) g. ,*+ *6. 3he S.;. unit of energy is the oule- L. 1 L 1 kgMm&As&. nother energy unit- the erg- was once in widespread use. 1 erg 1 gMcm&As&. Calculate the number of ergs in 1 L- showing all your work. ns% 1 L 140 erg +4. Classify the following properties of hydrogen gas as either intensi(e or extensi(e. a. the mass of the gas sample b. the a(erage speed of a molecule in the sample c. temperature d. density e. number of molecules present ns% a. $ b. ; c. ; d. ; e. $ +1. n e(acuated &0, m7 glass bulb weighs 1&6.,)0+ g. Hilled with an unknown gas- the bulb weighs 1)4.4)12 g. Calculate the gas density in gA7- and express it with an appropriate number of significant figures. ns% 1.*) gA7
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Chapter 1 Keys to the Study of Chemistry
+&. Nse the relationship between temperatures in Celsius and Hahrenheit to calculate the temperature at which a. the numerical (alue is the same on both scales. b. the Hahrenheit number is exactly twice the Celsius number. ns% a. *4.GH 5 *4.GC b. )&4.GH 1,4.GC +). Write the following numbers and results in scientific notation- with appropriate significant figures. a. ,+* b. 1&)*+,4 c. 4.444444,0) d. 4.44&+64 e. &44.* f. &,4.4 g. πr &- where r 2.0 cm h. &).&* O 12., 5 + ns% a. ,.+* × 14& b. 1.&)*+, × 14, c. ,.0) × 1450 d. &.+64 × 145) e. &.44* × 14& f. &.,44 × 14& g. &.* × 14& cm& h. ).0 × 141 +*. Write the following numbers and results in standard notation- with appropriate significant figures. a. 0.2+ × 145) b. 0.2+ × 14* c. +.6&4 × 14) d. e. 0.44 × 145+ f. circumference of a circle- &πr- where r 2.0 cm g. ns% a. 4.4402+ b. 02+44 c. +6&4. d. 02+ e. 4.4444044 f. ++ cm g. &&644
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Chapter 1 Keys to the Study of Chemistry
++. ;n each of the sets below- choose the one uantity or number which is exact. a. i.! the human population ii.! the distance in light years from the sun to lpha Centauri- a nearby star iii.! the winning time for the 144 m dash in the
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Chapter 1 Keys to the Study of Chemistry
,*. 3he number ,.4**2- rounded to ) decimal places- becomes ,.4*+. ns% 3rue ,+. 3he number ,.4**2- rounded to & decimal places- becomes ,.4+. ns% Halse ,,. 3he weight of a coin measured as 1.6,&)+ g on one balance is definitely more accurate than a weight measurement of 1.6+ g on another balance. ns% Halse
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