Equilibrium Multiple Choice January 1999 7. Consider the following graph:
When equilibrium is reached, the rate of the forward reaction is A. 0.00 mol/min B. 0.2mol/min C. !.0 mol/min ". #.0 mol/min 8. Consider the following equilibrium:
2$%2 &g' $2%( &g' ) energ* +he equilibrium will shift to the left as a result of A. adding a catal*st. B. increasing the olume. C. remoing some $2%(. ". decreasing the temperature. 9. -thene, C2(, can be produced in the following industrial s*stem:
C2 &g' ) energ* C2( &g' ) 2 &g' +he conditions that are necessar* to maimi1e the equilibrium *ield of C2( are A. low temperature and low pressure. B. low temperature and high pressure. C. high temperature and low pressure. ". high temperature and high pressure.
10. Consider the following equilibrium:
2 &g' ) 2 &g' 2 &g' +he olume of the equilibrium equ ilibrium s*stem is increased and a new equilibrium is established. Compared to the rates in the original equilibrium, which of the following d escribes the rates of the forward and reerse reactions in the new equilibrium3
11. 11. Consider the following equilibrium:
$2 &g' ) #2 &g' 2$# &g' ) energ* Certain conditions proide less than !04 *ield of $# at equilibrium. Which of the following describes this equilibrium3
12. Which of the following best describes the relationship between 5 eq eq and temperature for an endothermic reaction3
10. Consider the following equilibrium:
2 &g' ) 2 &g' 2 &g' +he olume of the equilibrium equ ilibrium s*stem is increased and a new equilibrium is established. Compared to the rates in the original equilibrium, which of the following d escribes the rates of the forward and reerse reactions in the new equilibrium3
11. 11. Consider the following equilibrium:
$2 &g' ) #2 &g' 2$# &g' ) energ* Certain conditions proide less than !04 *ield of $# at equilibrium. Which of the following describes this equilibrium3
12. Which of the following best describes the relationship between 5 eq eq and temperature for an endothermic reaction3
April 1999 7. Consider the following 6- diagram for a reersible reaction:
Which of the following describes this reaction3
8. Consider the following equilibrium:
2$%&g' ) Br 2&g' 2&g' ) energ* +he equilibrium will shift to the left as a result of
2$%Br &g' &g'
A. adding a catal*st. B. remoing $%Br. C. increasing the olume. ". increasing the temperature. 9. Consider the following equilibrium:
$2&g' ) %2&g' ) energ* 2$%&g' When the temperature is increased, the equilibrium shifts to the A. left and 5 eq eq increases. B. left and 5 eq eq decreases. C. right and 5 eq eq increases. ". right and 5 eq eq decreases.
10. Consider the following equilibrium:
2C%&g' ) %2&g' 2C%2 &g' ) energ* 7ome C%2 is added to the equilibrium s*stem at constant olume and a new equilibrium is established. Compared to the original equilibrium, the rates of the forward and reerse reactions for the new equilibrium hae
11. 11. An indication that an equilibrium s*stem faours the products is a
A. large 5 eq eq . B. positie ∆. C. one step mechanism. ". low actiation energ*. energ*. 12. +he relationship between 5 eq eq and the pressure of a gaseous equilibrium at constant temperature can be described b*
13. Consider the following equilibrium:
2$%2&g' $2%(&g' A !.00 8 flas9 contains 0.0#0 mol $%2 and 0.0(0 mol $2%( at equilibrium. +he alue of 5 eq eq is A. 0.02# B. 0. C. !.# ". ((
June 1999 7. Consider the following reaction: $2&g' ) #2&g' 2$# &g' ) energ* Which of the following describes the changes in enthalp* and entrop* as the reaction proceeds3
8. Consider the following equilibrium:
27%2&g' ) %2&g' 27%#&g' ) energ* Which of the following will cause this equilibrium to shift to the left3 A. adding a catal*st B. adding some 7%2 C. increasing the olume ". decreasing the temperature 9. ;ethanol, C#%, can be produced b* the following:
C%&g' ) 22&g' C#%&g' ) energ* +he conditions that are necessar* to maimi1e the equilibrium *ield of C#% are A. low temperature and low pressure. B. high temperature and low pressure. C. low temperature and high pressure. ". high temperature and high pressure. 10. A catal*st is added to a s*stem alread* at equilibrium. ow are the forward and reerse reaction rates affected b* the addition of the catal*st3
11. Consider the following reaction:
22&g' ) %2&g' 22%&l' What is the equilibrium constant epression for the reaction3 A. 5eq < =2>2=%2> =2>2=%2> B. 5eq< ??????????????? =2%>2 =2%>2 C. 5eq< ??????????????? =2>2=%2> ! ". 5eq< ?????????????????? =2>2=%2>
12. +he relationship between 5 eq and temperature for an eothermic reaction is represented b*
13. Consider the following equilibrium:
2$%Br &g' 2$%&g' ) Br 2&g' 5 eq < .( @ !0?2 At equilibrium, a !.00 8 flas9 contains 0.0#0 mol $%Br and 0.0#0 mol $%. ow man* mol Br 2 are present3 A. !. ×!0−# mol B. .( ×!0−2 mol C. #.0 ×!0−2 mol ". (. ×!0−! mol
August 1999 7. At different conditions, the relationship between the forward and reerse rates of reaction in an equilibrium s*stem can be represented b*
8. Consider the following equilibrium:
($#&g' ) %2&g' ($%&g' ) 2% &g' ) energ* Which of the following will cause the equilibrium to shift to the left3 A. adding 2%&g' B. remoing some $% & g) C. increasing the olume ". decreasing the temperature 9. Consider the following equilibrium:
2$%&g' ) %2&g'
2$%2 &g' ) energ*
When the olume of the container is increased, the equilibrium shifts to the A. left and 5 eq decreases. B. right and 5 eq increases. C. left and 5 eq remains constant. ". right and 5 eq remains constant.
10. Consider the following equilibrium:
(Cl &g' ) %2&g' 22%&g' ) 2Cl2 &g' ) energ* +he temperature of the equilibrium s*stem is increased and a new equilibrium is established. +he rates of the forward and reerse reactions for the new equilibrium compared to the original equilibrium hae
11. Consider the following reaction:
2g&g' ) %2&g' 2g%&s' +he equilibrium constant epression for the reaction is
12. +he alue of 5 eq changes when
A. a catal*st is added. B. the temperature changes. C. the surface area changes. ". the concentration of reactants changes. 13. Consider the following equilibrium:
6Cl&g' 6Cl#&g' ) Cl2&g' A !.00 8 flas9 contains 0.0200 mol 6Cl, 0.000 mol 6Cl# and 0.000 mol Cl2 at equilibrium. +he alue of 5 eq is A. 0.!2 B. 2.0 C. .00 ". .00
January 2000 7. Consider the following equilibrium:
$2&g' ) 2%2&g' 2$%2&g' -qual moles of $2 and %2 are added, under certain conditions, to a closed container. Which of the following describes the changes in the reerse reaction which occur as the s*stem proceeds toward equilibrium3
8. A chemical equilibrium is described as d*namicD because
A. maimum randomness has been achieed. B. the pressure and temperature do not change. C. both reactants and products continue to form. ". the concentrations of chemical species remain constant. 9. Which of the following reactions results in an entrop* increase3
A. 2C&s' ) %2&g' 2C%&g' B. $2&g' ) 22&g' $2(&l' C. 27%2&g' ) %2&g' 27%#&g' ". Ag) &aq' ) Cl? &aq' AgCl&s' 10. Consider the following equilibrium:
C#C%%&aq' ) 2%&l' C#C%%? &aq' ) #%) &aq' ) heat A stress was applied at time t ! and the data was plotted on the following graph:
+he stress that was imposed at time t ! is the result of A. the addition of Cl. B. decreasing the temperature. C. the addition of $aC#C%%.
". increasing the olume of the container. 11. Consider the following potential energ* diagram for an equilibrium s*stem:
When the temperature of the s*stem is increased, the equilibrium shifts to the A. left and the 5 eq increases. B. left and the 5 eq decreases. C. right and the 5 eq increases. ". right and the 5 eq decreases. 12. What is the 5 eq epression for the following equilibrium3
#Ee&s' ) (2%&g'
Ee#%(&s' ) (2&g'
13. Consider the following equilibrium:
2%#&g' #%2&g' 5eq< nitiall*, 0.!0 mole of %# and 0.!0 mole of %2 are placed in a !.08 container. Which of the following describes the changes in concentrations as the reaction proceeds toward equilibrium3
April 2000 7. Which of the following applies to a chemical equilibrium3
. . .
Eorward and reerse reaction rates are equal -quilibrium can be achieed from either direction ;acroscopic properties are constant
A. onl* B. and onl* C. and onl* ". , and 8. n which of the following will the driing forces of minimum enthalp* and maimum entrop* oppose one another3
A. 2C&s' ) %2&g' 2C%&g' B. 2$2&g' ) %2&g' 2$2%&g' C. 2C%&g' ) %2&g' 2C%2&g' ". 2C%2&g' ) 2%&g' 2C2&g' ) %2&g'
∆<
?22!9F ∆< )!(9F ∆< ?9F ∆< )#!229F
9. Consider the following equilibrium:
2Cr%( 2? &aq' ) 2#%) &aq' &*ellow'
Cr 2% 2? &aq' ) #2%&l' &orange'
An un9nown solution is added to an orange equilibrium sample until the sample turns *ellow. +he un9nown solution could be A. 5$%# B. $a% C. $( $%# ". C#C%% 10. Ammonia, $# , is produced b* the following reaction:
$2&g' ) #2&g' 2$#&g' ) energ* Which of the following would result in the highest concentration of ammonia at equilibrium3 A. increasing the temperature and increasing the pressure B. decreasing the temperature and increasing the pressure C. increasing the temperature and decreasing the pressure ". decreasing the temperature and decreasing the pressure
11. What is the 5 eq epression for the following reaction3
7n%2&s' ) 2C%&g'
7n&s' ) 2C%2&g'
12. Consider the following reaction:
C&s' ) 22&g' C(&g' ∆ < ?(.5F Which of the following will cause an increase in the alue of 5 eq3 A. increasing =2> B. decreasing the olume C. finel* powdering the C &s' ". decreasing the temperature 13. Consider the following equilibrium:
2&g' ) 2&g'
2&g'
At equilibrium =2> < 0.00220 mol/8, =2> < 0.00220 mol/8 and => < 0.0!mol/8. +he alue of 5 eq is A. #.!0 @ !0?( B. !. @ !0?2 C. .0# @ !0! ". #.22 @ !0# June 2000 7. Consider the following equilibrium:
2$%Cl&g' 2$%&g' ) Cl2&g' A flas9 of fied olume is initiall* filled with $%Cl&g', $%&g' and Cl2&g' . When equilibrium is reached, the pressure has increased. +o reach equilibrium, the reaction proceeded to the A. left because +rial 5 eq was less than 5 eq. B. right because +rial 5 eq was less than 5 eq. C. left because +rial 5 eq was greater than 5 eq .
". right because +rial 5 eq was greater than 5 eq . 8. n which of the following do both minimum enthalp* and maimum entrop* factors faour the reactants3 A. Cl2&g'
Cl2&aq'
B. C&s' ) 2%&l' C. 2C%2&g' ) #2%&g' ". $a2C%#&s' ) Cl &aq'
C%&g' ) 2&g' C2%&l' ) #%2 2$aCl &aq' ) C%2&g' ) 2%&l'
∆ <
?2 9F
∆ <
)!#!9F
∆ <
)!2#9F
∆ <
?29F
9. Consider the following equilibrium:
2 &g' ) 2&g' 2&g' Which graph represents what happens when some is remoed and a new equilibrium is established3
10. Consider the following equilibrium:
C%&g' ) 2%&g' C%2&g' ) 2&g' What will cause a shift in the equilibrium3 A. adding a catal*st B. changing olume C. adding an inert gas ". changing temperature 11. +he equilibrium epression for a reaction is
=)> 5eq < ??????????????????? =Bi#)>2=27># +he reaction could be A. ) ) Bi7&s' B. ) &aq' ) Bi27# &s' C. 2Bi #) &aq' ) #27 &aq'
2Bi #) &aq' ) #27&g' 2Bi #) &aq' ) #27&g' Bi27#&s' ) )&aq'
G< ∆
?(!9F
". 2Bi #) &aq' ) #27 &aq' Bi27# &aq' ) ) &aq' 12. Consider the following equilibrium: Co&2%' 2) &aq' ) (Cl? CoCl(2? &aq' ) 2%&l' &pin9' &blue' When the temperature is increased, the solution turns a dar9 blue. Based on this obseration, the reaction is A. eothermic and the 5 eq has increased. B. eothermic and the 5 eq has decreased. C. endothermic and the 5 eq has increased. ". endothermic and the 5 eq has decreased. 13. Consider the following equilibrium:
2%#&g' #%2&g' 5eq < # What is the concentration of %# when the equilibrium concentration %f %2 is .0 @ !0?2 mol/83 A. 2.( @ !0?# mol/8 B. (.0 @ !0?2 mol/8 C. .0 @ !0?2 mo/8 ". .0 @ !0?2 mol/8 August 2000 7. Which of the following does not appl* to all chemical equilibrium s*stems3
A. +he* are closed. B. +he macroscopic properties are constant. C. Eorward and reerse reaction rates are equal. ". +here are equal concentrations of reactants and products. 8. Consider the following equilibrium:
2$%Cl&g'
2$% &g' ) Cl2&g'
A flas9 is filled with $%Cl, $% and Cl2. nitiall* there was a total of .0 moles of gases present. When equilibrium is reached, there is a total of .0 moles of gases present. Which of the following eplains this obseration3 A. +he reaction proceeded left because the +rial 5 eq H 5 eq B. +he reaction proceeded left because the +rial 5 eq I 5 eq C. +he reaction proceeded right because the +rial 5 eq H 5 eq ". +he reaction proceeded right because the +rial 5 eq I 5 eq
9. Consider the following reaction: C# &g' ) %2&g' #C%2&g' ) (2%&g' Which of the following applies to the forward reaction3
A. B. C. ".
Entropy increases increases decreases decreases
∆H =
?22029F
Enthalpy increases decreases increases decreases
10. Consider the following equilibrium:
2$%2&g' $2%( &g' ) energ* +he number of moles of $%2 at equilibrium could be increased b* A. adding $2%( B. adding a catal*st. C. decreasing the temperature. ". decreasing the olume b* increasing the pressure. 11. What is the 5 eq epression for
7b#) &aq' ) Cl?&aq' ) 2%&l'
7b%Cl &s' ) 2) &aq'
12. Consider the following equilibrium:
2 &g' ) 2&g' 2&g' 5eq < 0.0 What is the alue 5 eq for the reaction rewritten as: 2 &g' A. J0.0 B. 0.0200 C. 2.0 ". 0.0
2&g' ) 2&g' 5eq < 3
13. Consider the following equilibrium:
2$%2&g' $2%( &g' 5eq < !.! +he equilibrium concentration of $%2 is 0.0 mol/8. Calculate the equilibrium Concentration of $2%( &g'.
A. 0.22 mol/8 B. 0.2 mol/8 C. 0.(# mol/8 ". 0. mol/8 January 2001 7. All chemical equilibriums hae:
. . .
rates that are continuing to change an equilibrium constant epression equal concentrations of products and reactants
A. onl* B. onl* C. and onl* ". and onl* 8. Erom the following, select the situation where both enthalp* and entrop* faour the reaction toward products:
A. B. C. ".
-nthalp* increasing increasing decreasing decreasing
-ntrop* increasing decreasing decreasing increasing
9. Consider the following equilibrium:
2$%&g' ) Br 2&g' 2$%Br &g' ) energ* +he equilibrium will shift to the left as a result of A. adding a catal*st. B. adding some $% &g'. C. increasing the olume. ". decreasing the temperature.
10. Consider the following equilibrium:
6Cl#&g' ) #$#&g' 6&$2'# &g' ) #Cl&g' +he olume of the equilibrium s*stem is increased and a new equilibrium is established. ow hae the rates been affected3
A. B. C. ".
Kate &forward' increased decreased decreased did not change
Kate &reerse' decreased increased decreased did not change
11. 7tarting with equal moles of reactants, which of the following equilibrium s*stems most faours the reactants3
A. 7%2&g' ) $%2&g'
7%# &g' ) $%&g'
5eq< #.(
B. C%&g' ) 2%&g'
C%2&g' ) 2&g'
5eq< #!.(
C. 2&g' ) 2&g' ". $2 &g' ) %2&g'
2&g'
5eq< !0 5eq< !.0@!0?#!
2$%&g'
12. Consider the following equilibrium reaction:
$2%(&g'
2$%2&g'
At time t!, heat is applied to the s*stem. Which of the following best describes the equilibrium reaction and the change in 5 eq3 A. eothermic and 5 eq increases B. eothermic and 5 eq decreases C. endothermic and 5 eq increases ". endothermic and 5 eq decreases
13. Consider the following:
6Cl#&g' ) Cl2&g' 6Cl&g' 5eq < 0.( at 22LC nitiall*, a !.008 flas9 is filled with 0.!00mol 6Cl#, 0.!00mol Cl2, and 0.!00mol 6Cl at 22LC. Mse 5 Trial to predict the change in =Cl2> as equilibrium is established.
April 2001 7. Consider the following equilibrium reaction:
2Cl&g' 2&g' ) Cl2&g' 7ome Cl is added to an empt* flas9. ow do the reaction rates change as the s*stem approaches equilibrium3
A. B. C. ".
Eorward rate increases increases decreases decreases
Keerse rate increases decreases increases decreases
8. n an equilibrium s*stem, continuing microscopic changes indicate that the equilibrium is
A. d*namic. B. complete. C. eothermic. ". spontaneous. 9. Consider the following equilibrium:
(Cu%&s' ) energ* 2Cu2%&s' ) %2&g' +he equilibrium will shift to the right as a result of A. adding Cu% &s'. B. remoing %2 &g'. C. adding a catal*st. ". decreasing the temperature.
10. Consider the following equilibrium:
$2&g' ) #2&g'
2$#&g'
+he olume of the s*stem is decreased. +he equilibrium shifts A. left since the reerse rate is greater than the forward rate. B. left since the forward rate is greater than the reerse rate. C. right since the reerse rate is greater than the forward rate. ". right since the forward rate is greater than the reerse rate. 11. Consider the following equilibrium:
27%#&g' 27%2&g' ) %2&g' ∆Η = +1989F When the temperature is increased, the equilibrium will shift A. left with 5 eq becoming larger. B. right with 5 eq becoming larger. C. left with 5 eq becoming smaller. ". right with 5 eq becoming smaller. 12. 7tarting with equal concentrations of reactants, which of the following will be closest to completion at equilibrium3
A. C%&g' ) Cl2&g'
C%Cl2&g'
5eq<22
B. 6Cl#&g' ) Cl2&g'
6Cl&g'
5eq< 2. @ !0?2
C. C%&g' ) Cl2&g'
C%Cl2&g'
5eq<(. @ !0 J
". C#%2 &g' ) $%2&g'
C#%2 $%2&g'
5eq<2.! @ !0 ?!2
13. Consider the following equilibrium:
2C%E2&g' C%2&g' ) CE(&g' At equilibrium, a !.008 container contains .0 @ !0?( mol C%E2, !.00 @ !0?# mol C%2, and !.00 @ !0?# mol CE(. What is the alue of 5eq3 A. .0 @ !0?( B. !.(! @ !0?# C. 0.00 ". 2.00
June 2001 7. Consider the following reaction:
2Cl&g' 2&g' ) Cl2&g' A closed container is initiall* filled with Cl &g'. What are the changes in the rate of the forward reaction and =2>, as the s*stem approaches equilibrium3
8. +he entrop* of a s*stem is a term used to describe
A. randomness. B. heat content. C. aerage 9inetic energ*. ". stored chemical energ*. 9. Consider the following equilibrium:
Cu2) &aq' ) (Br ?&aq' ) energ* Blue
colourless
CuBr ( 2?&aq' green
Which of the following will cause this equilibrium to change from blue to green3 A. adding $aBr &s' B. adding $a$%# &s' C. adding a catal*st ". decreasing the temperature 10. Consider the following equilibrium:
$i&s' ) (C%&g'
$i&C%'2&l'
∆Η =−160.89F
Which of the following will cause this equilibrium to shift to the left3 A. add some C% B. decrease the olume C. remoe some $i&C%'( ". increase the temperature
11. Consider the following equilibrium:
$2%(&g' ) energ* 2$%2&g' Which of the following shows the relationship between concentration and time as a result of adding a catal*st at time t < !3
12. Consider the following equilibrium:
27&g' ) 2&s' 2&g' ) 7&s' What is the equilibrium epression for this reaction3 =>2 A 5eq =27> B. 5eq2 =>2=7> C. 5eq6=2> =27>6=2> ". 5eq2=7> 13. Consider the following equilibrium:
C%&g' ) 2%&g' C%2&g' ) 2&g' 5eq < .0 At equilibrium, the =C%>< 0.20mol/8, =2%>< 0.#0mol/8, and =2>< 0.0mol/8. Calculate the equilibrium =C%2>. A. 0.0!# mol/8
C. 0.## mol/8
B. 0.0 mol/8 14. Consider the following:
". !.0mol/8
C%2&g' ) CE(&g' 2C%E2&g' n a reaction container the initial concentrations are: =C%2>< 0.0mol/8, =CE(>< 0.0mol/8, =C%E2>< 0.#0 mol/8
5eq< 0.0
+o reach equilibrium, the reaction will proceed A. left since +rial 5 eq I K eq B. left since +rial 5 eq H K eq C. right since +rial 5 eq I K eq ". right since +rial 5 eq H K eq August 2001 7. All chemical equilibriums must hae
A. 5 eq < ! B. =reactants><=products>. C. rate forward < rate reerse. ". mass of reactants < mass of products. 8. Consider the following equilibrium reaction:
(Cl&g' ) %2&g'
22%&g' ) 2Cl2&g' ) !!!.(9F
Eor the forward reaction, how do enthalp* and entrop* change3
A. B. C. ".
-nthalp* increases decreases increases decreases
-ntrop* decreases decreases increases increases
9. Consider the following equilibrium:
C#Cl&aq' ) %? &aq' C#%&aq' ) Cl?&aq' +he equilibrium will shift to the left as a result of the addition of A. $%# B. 5$%# C. $a% ". C#Cl
10. Consider the following equilibrium at 2LC :
$i&s' ) (C%&g'
$i&C%'(&l'
Eor this reaction A. 5eq < =C%>( ! B. 5eq< ?????????????? =C%>(
=$i&C%'(&l'> C. 5eq< ???????????????? =C%>( =$i> =$i&C%'(&l'> ". 5eq< ???????????????? =C%>( 11. Consider the following equilibrium:
2C%E2&g' C%2&g' ) CE(&g' 5eq<2.00 At equilibrium, =C%2><0.00mol/8 and =CE(><0.00mol/8. What t is =C%E2> at equilibrium3 A. 0.00!2 mol/8 B. 0.0# mol/8 C. 0.00 mol/8 ". 0.22 mol/8 12. Consider the following equilibrium:
2%&g' ) Cl2%&g' 2%Cl&g' 5eq< 0.000 nitiall*, a !.008 flas9 is filled with 0.!00mol of 2%, 0.!00mol of Cl2% and 0.!00mol of %Cl. As equilibrium is established, the reaction proceed s to the A. left because 5 Trial H 5 eq B. left because 5 Trial I 5 eq C. right because 5 Trial H 5 eq ". right because 5 Trial I 5 eq
January 2002 7. Consider the following:
27%2&g' ) %2&g' 27%#&g' nitiall*, 7%# is added to an empt* flas9. ow do the rate of the forward reaction and =7%#> change as the s*stem proceeds to equilibrium3
8. Consider the following reaction:
$2&g' ) #2&g' 2$#&g' ) energ* What positions do minimum enthalp* and maimum entrop* tend toward3
se the !ollo"in# equilibrium equation to ans"er questions 9 and 10.
C%2&g' ) 2&g'
2%&g' ) C%&g'
9. Which two stresses will each cause the equilibrium to shift to the left3
A. increase =2> , increase =C%> B. decrease =2> , increase =2%> C. increase =C%2> , decrease =C%> ". decrease =C%2> , decrease =2%>
10. Which of the following graphs represents the forward rate of reaction when 2%& g ' is added to the aboe equilibrium at time t < ! 3
11. Consider the following:
2$# &g' $2&g' ) #2&g' nitiall*, some $# is placed into a !.08 container. At equilibrium there is 0.0#0mol $2 present. What is the =2> at this equilibrium3 A. 0.0!0 mol/8 B. 0.0#0 mol/8 C. 0.00 mol/8 ". 0.00 mol/8 12. Which reaction has the following equilibrium epression3
=$%2>(=2%> 5eq(=%2> A. ($#&g' ) %2&g' B. ($#&aq' ) %2&g'
($%2&g' ) 2%&g' ($%2&aq' ) 2%&l'
C. ($%2&aq' ) 2%&l'
($#&g' ) %2&g'
". ($%2&g' ) 2%&g'
($#&g' ) %2&g'
13. What will cause the 5 eq for an eothermic reaction to increase3
A. increasing =reactants> B. decreasing =products> C. increasing the temperature ". decreasing the temperature
April 2002 7. Consider the following:
2&g' ) 2&g' 2&g' nitiall*, is added to an empt* flas9. ow do the rates of the forward and reerse reactions change as the s*stem proceeds to equilibrium3
8. Consider the following reaction: 22%&l' ) energ* 22 &g' ) %2&g'
"etermine the enthalp* and entrop* changes for the aboe reaction3
se the !ollo"in# equilibrium equation to ans"er questions 9 and 10.
2C%&g' ) %2&g'
2C%2&g' ) energ*
9. Which of the following two stresses will each cause the s*stem to shift to the right3
A. increase temperature, increase olume B. decrease temperature, increase olume C. increase temperature, decrease olume ". decrease temperature, decrease olume
10. Which of the following shows the forward rate of reaction when the temperature of the s*stem is increased at time t < ! 3
11. Consider the following:
27%2&g' ) %2&g'
27%#&g'
nitiall*, 0.0#0mol 7%2 and 0.0#0mol %2 are placed into a !.08 container. At equilibrium, there is 0.020 mol %2 present. What is the =7%2> at equilibrium3 A. 0.0!0 mol/8 B. 0.020 mol/8 C. 0.0#0 mol/8 ". 0.0(0 mol/8 12. What is the equilibrium epression for the following s*stem3
CaC%#&s' ) 2E&g'
CaE2&s' ) 2%&g' ) C%2&g'
=E>2 A. 5eq=C%2>
=2%>=C%2> C. 5eq< ??????????????? =CaC%#>=E>2
=2%>=C%2> B. 5eq2
=CaE2> =2%>=C%2> ". 5eq< ?????????????????????? =CaC%#>=E>2
13. What will cause the 5 eq for an endothermic reaction to decrease3
A. adding a catal*st B. increasing the surface area C. increasing the temperature ". decreasing the temperature
June 2002 7$ Consider the following :
2Br &g' ⇄ 2&g' ) Br 2&g' nitiall*, Br is added to an empt* flas9. ow do the rate of the forward reaction and the =Br> change as the s*stem proceeds to equilibrium3 Eorward Kate
=Br>
A.
"ecreases
"ecreases
B.
"ecreases
ncreases
C.
ncreases
ncreases
".
ncreases
"ecreases
se the !ollo"in# equilibrium equation to ans"er questions 8 and 9.
27%2&g' ) %2&g' ⇄ 27%#&g' ) energ*
8$ Which of the following two stresses will each cause the s*stem to shift to the right3
A. decrease temperature, decrease =%2> B. increase temperature, increase =7%#> C. increase temperature, decrease =7%#> ". decrease temperature, increase =7%2> 9$ Which of the following graphs shows the reerse rate of reaction when a catal*st is added to the equilibrium at time < t!3
10$ Consider the following:
3 2$2&g' ) %2&g' ) energ* ⇄ 2$2%&g'
What positions do minimum enthalp* and maimum en trop* tend toward3
A.
;inimum -nthalp* products
;aimum -ntrop* products
B.
products
reactants
C.
reactants
products
".
reactants
reactants
11$ Consider the following:
2&g' ) 2&g' ⇄ 2&g' nitiall*, some is placed into a !.08 container. At equilibrium there is 0.0!0 mol 2, 0.0!0 mol 2 and 0.00 mol present. ow man* moles of were initiall* added to the container3 A. 0.00 mol B. 0.00 mol C. 0.00 mol ". 0.00 mol 12$ What is the equilibrium epression for the following s*stem3
(Ee&s' ) #%2&g' ⇄ 2Ee2%#&s' A. 5 eq < =%2># ! B. 5 eq < =%2># =Ee2%#>2 C. 5eq < =Ee>(=%2># =2Ee2%#> ". 9eq < =(Ee>=#%2>
13$ What will cause the alue of 5 eq for an endothermic reaction to increase3
A. increasing =products> B. decreasing =products> C. increasing the temperature ". decreasing the temperature 14$ Consider the following equilibrium:
$2%(&g' ⇄ 2$%2&g' An equilibrium miture contains (.0 N !0?2 mol $2%( and !. N !0?2 mol $%2 n a !.08 flas9. What is the alue of 5 eq3 A. . N !0?# B. #. N !0?! C. . N !0?! ". !. N !02 August 2002 7$ Consider the following:
2$#&g' ⇄ $2&g' )#2&g' nitiall*, $# is added to an empt* flas9. ow do the rates of the forward and Keerse reactions change as the s*stem proceeds to equilibrium3 Eorward Kate
Keerse Kate
A.
ncreases
ncrease
B.
ncreases
"ecreases
C.
"ecreases
ncreases
".
decreases
decreases
8$ Consider the following:
3
2&g' ) Br 2&l' ⇄ 2Br &g' ) energ* What positions do minimum enthalp* and maimum en trop* tend toward3
A.
;inimum -nthalp* 6roducts
;aimum -ntrop* 6roducts
B. 6roducts Keactants C. Keactants 6roducts ". Keactants Keactants se the !ollo"in# equilibrium equation to ans"er questions 9 and 10. 2&g' ) 2&g' ⇄ 2&g' ) energ*
9$ Which of the following stresses will not cause s shift in equilibrium3
A. decrease =2> B. increase =2> C. decrease olume ". increase temperature 10$ Which of the following shows the reerse rate of reaction when the olume is decreased at time < t!3
11$ Consider the following:
27%#&g' ⇄ 27%2&g' ) %2&g' nitiall*, some 7%# is placed into a #.08 container. At equilibrium there is 0.0#0 mol 7%2 present. What is the =%2> at equilibrium3 A. 0.000 mol/8 B. 0.0!0 mol/8 C. 0.0! mol/8 ". 0.0#0 mol/8
12$ Which reaction has the following equilibrium epression3
5 eq <
=6Cl> =6Cl#>=Cl2>
A. 6Cl#&g' ) Cl2&g' ⇄ 6Cl&g' B. 6Cl#&g' ) Cl2&l' ⇄ 6Cl&g' C. 6Cl&g' ⇄ 6Cl#&g' ) Cl2&g' ". 6Cl&g' ⇄ 6Cl#&g' ) Cl2&l' 13$ What will cause the alue of 5 eq for an eothermic reaction to decrease3
A. increasing the pressure B. increasing the temperature C. decreasing the temperature ". decreasing the surface area 14$ Consider the following equilibrium:
2&g' ) 2&g' ⇄ 2&g' An equilibrium miture contains !.0 N !0?# mol 2, 2.0 N !0?# mol 2 And !.0 N !0?2 mol in a !.08 container. What is the alue of 5 eq3 A. 2.0 N !0?2 B. .0 N !0! C. 0 N !0# ". !.0 N !0(
January 2003
7$ Which of the factors below is not a condition necessar* for equilibrium3
A. a closed s*stem B. a constant temperature C. equal forward and reerse reaction rates ". equal concentrations of reactants and products
8$ n order for a chemical reaction to go to completion, how must the entrop* and enthalp* change3
A. B. C. ".
-ntrop* ncreases ncreases "ecreases "ecreases
-nthalp* ncreases "ecreases ncreases "ecreases
9$ Consider the following equilibrium s*stem:
27%2&g' ) %2&g' ⇄ 27%#&g' 5 eq < !.2 N !0( f additional 7%2 is added to the s*stem, what happens to the equilibrium and +he alue of 5 eq3
A. B. C. ".
-quilibrium 7hifts left 7hifts right 7hifts right $o change
5eq "ecreases ncreases $o change $o change
10$ Consider the following equilibrium s*stem:
$2&g' ) #2&g' ⇄ 2$#&g' "etermine the changes in reaction rates as a catal*st is added. Eorward Kate
Keerse Kate
A.
ncreases
ncreases
B.
ncreases
"ecreases
C.
"ecrease
ncreases
".
"ecreases
"ecreases
11$ Consider the following equilibrium s*stem:
25Cl%#&s' ⇄ 25Cl&s' ) #%2&g'
Which of the following is the equilibrium constant epression3 A. 5 eq < =%2># ! B. 5 eq < =%2># =5Cl%#>2
C. 5 eq <
=5Cl>2=%2>#
=5Cl>2=%2># ". 5 eq < =5Cl%#>2
12$ Consider the following equilibrium:
C%2&g' ) 22%&g' ⇄ C(&g' ) 2%2&g' Which of the options below indicates that the reactants are faoured3 A. 5 eq is aero. B. 5 eq is er* large. C. 5 eq is slightl* less than !. ". 5 eq is slightl* greater than !. 13$ Consider the following equilibrium:
$2%(&g' ) energ* ⇄ 2$%2&g' ow are 5 eq is =$2%(> affected b* the addition of $e &an inert gas' into the Container at constant olume. 5 eq
=$2%(>
A.
$o change
$o change
B.
$o change
ncreases
C.
ncreases
"ecreases
".
decreases
increases
14$ Consider the following equilibrium:
Cl2&g' ) 2$%&g' ⇄ 2$%Cl&g'
5 eq < .0
At equilibrium, =Cl2> < !.0; and =$%> < 2.0;. What is the =$%Cl> at equilibrium3
A. 0.0 ; B. 0. ; C. (. ; ". !0 ; April 2003 7$ Eor the equilibrium s*stem below:
Cu&s' ) 2Ag)&aq' ⇄ 2Ag&s' ) Cu)2&aq' We would 9now the s*stem is at equilibrium because A. =Cu)2> < =Ag)> B. 2=Cu)2> < =Ag)> C. the mass of Cu&s' remains constant. ". the mass of the entire s*stem remains constant. 8$ Eor the reacting s*stem:
28i&s' ) 22%&l' O 28i%&aq' ) 2&g'
P < ?(## 5F
What will entrop* and enthalp* factors faour3
A. B. C. ".
-ntrop* 6roducts 6roducts Keactants Keactants
-nthalp* Keactants 6roducts Keactants 6roducts
9$ Consider the following equilibrium:
$2&g' ) #2&g' ⇄ 2$#&g' f some $e gas is added at a constant olume then how will =$2>, =2> and 5 eq
be affected3 =$2>
=2>
5 eq
A.
ncreases
ncreases
"ecreases
B.
"ecreases
"ecreases
ncreases
C.
"ecreases
ncreases
"oes not change
".
"oes not change
"oes not change
"oes not change
10$ What is the effect of adding a catal*st to an equilibrium s*stem3
A. +he alue of -a increases. B. +he alue of 5 eq increases. C. Eorward and reerse rates increase. ". +he concentration of products increases. 11$ Consider the following equilibrium:
2Cr%(2?&aq' ) 2)&aq' ⇄ Cr 2%2?&aq' ) 2%&l' What is the 5 eq epression3 =Cr%(2?>2=)>2 A. =Cr 2%2?> =Cr 2%2?> B. =Cr%(2?>2=)>2 =Cr 2%2?> C. =2Cr%(2?>=2)> =Cr 2%2?>=2%> ". =Cr%(2?>2=)>2
12$ A container is initiall* filled with pure 7%#. After a period of time, the following equilibrium is established:
27%2&g' ) %2&g' ⇄ 27%#&g'
5 eq < .0 N !02
What does this equilibrium miture contain3
A. mostl* products B. mostl* reactants # C.
2 reactants and
products
". equal amounts of reactants and products. 13$ Consider the following equilibrium:
2C%&g' ) %2&g' ⇄ 2C%2&g'
5 eq < (.0 N !0?!0
What is the alue of 5 eq for 2C%2&g' ⇄ 2C%&g' ) %2&g' 3 A. (.0 N !0?!0 B. 2.0 N !0? C. .0 N !0( ". 2. N !0 14$ Consider the following equilibrium:
2&g' ) Br 2&g' ⇄ 2Br &g' ow could the alue of 5 eq be increased3 A. add 2 B. add Br C. increase the pressure ". reduce the temperature
June 2003 7$ Consider the following 6- diagram:
P < ?#5F
dentif* the actiation energ* for the forward uncatal*sed reaction. A. ! B. 2 C. # ". ( 8$ n which of the following will entrop* and enthalp* factors faour the establishment of an equilibrium3 3
A. CaC%#&s' ) !5F O Ca%&s' ) C%2&g' 3
B. ;g&s' ) 2Cl&aq' O ;gCl2&aq' ) 2&g' ) (25F 3
C. 2C&s' ) 22&g' O C2(&g'
P < )2.#5F
3
". 2C2&g' ) %2&g' O (C%2&g' ) 2%&g'
P < ?!0 5F
9$ Consider the following equilibrium:
C%&g' ) 22&g' ⇄ C#%&g'
P < ?!5F
Which of the factors below would increase the concentration of C#% at equilibrium3 A. an addition of C% B. an increase in the olume C. a decrease in the pressure ". an increase in the temperature 10$ Consider the following equilibrium: 6Cl#&g' ) Cl2&g' ⇄ 6Cl&g'
f the olume of the s*stem is decreased, how will the reaction rates in the new
equilibrium compare with the rates in the original equilibrium3 Eorward Kate
Keerse Kate
A.
ncreases
ncreases
B.
ncreases
"ecreases
C.
"ecreases
"ecreases
".
"ecreases
ncreases
11$ Consider the following equilibrium: 2&g' ) 2&g' ⇄ 2&g' Colourless purple
P < ?!.5F
colourless
Which of the following would allow *ou to conclude that the s*stem has reached equilibrium3 A. +he pressure remains constant. B. +he reaction rates become 1ero. C. +he colour intensit* remains constant. ". +he s*stem shifts completel* to the right. 12$ Consider the following equilibrium: Ee2%#&s' ) #C%&g' ⇄ 2Ee&s' ) #C%2&g'
dentif* the equilibrium constant epression. =C%2># A. 5 eq <
=C%># =C%2>
B. 5 eq <
=C%> =C%2>#=Ee>2
C. 5 eq < =Ee2%#>=C%># =Ee2%#>=C%># ".5 eq < =C%2>#=Ee>2 13$ Consider the following equilibrium s*stem: 2$%&g' ) Cl2&g' ⇄ 2$%Cl&g'
P < ?5F
n which direction will the equilibrium shifts and what happens to the alue of
5 eq when the temperature of the s*stem is increased3 7hift
5eq
A.
Kight
ncreases
B.
Kight
"ecreases
C.
8eft
ncreases
".
8eft
"ecreases
14$ Consider the following equilibrium:
C%&g' ) 22&g' ⇄ C#%&g' At equilibrium it was found that =C%> < 0.!0 mol/8, =2> < 0.20 mol/8 and =C#%> < 0.002! mol/8. Which of the following is the eq uilibrium constant alue3 A. .( N !0?2 B. 0.# C. 2.! ". !0.0 August 2003 7$ Consider the following equilibrium:
2&g' ) 2&g' ⇄ 2&g' ow will the forward and reerse equilibrium reaction rates change when additional 2 is added to the s*stem3 Eorward Kate
Keerse Kate
A.
ncrease
ncrease
B.
ncrease
"ecrease
C.
"ecrease
ncrease
".
$o change
$o change
8$ Consider the following s*stem at equilibrium:
2%&g' ) C%&g' ⇄ C%2&g' ) 2&g' +his equilibrium will shift right as the result of the addition of some etra 2%. ow will this shift affect the concentrations of the other gases3
=C%>
=C%2>
=2>
A.
ncreases
"ecreases
"ecreases
B.
ncreases
ncreases
"ecreases
C.
"ecreases
ncreases
ncreases
".
"eceases
"ecreases
ncreases
9$ Consider the following equilibrium:
$2&g' ) #2&g' ⇄ 2$#&g' Which of the following factors will not alter the position of equilibrium3 A. a pressure decrease B. a temperature increase C. the presence of a catal*st ". the addition for more $2&g' 10$ Consider the following equilibrium:
$2%(&g' ) energ* ⇄ 2$%2&g' Which of the following graphs shows the result of increasing the temperature at time t!3
11$ Consider the following equilibrium and the table of eperimental data: $2%(&g' ⇄ 2$%2&g'
nitial =$2%(>
-quilibrium =$%2>
=$2%(>
=$%2>
+rial !
0.0(00
0.0000
0.0##
0.0!2
+rial 2
0.0200
0.000
0.0(2
0.0!(!
Which of the following represents the 5 eq alue3 A. (.( N !0?# B. #.! N !0?! C. .(2 N !0?! ". 2.! N !02 12$ Which of the following is least li9el* to faour the formation of products3
A. 22%&g' ⇄ 22&g' ) %2&g' B. $2%&g' ) $%2&g' ⇄ #$%&g' C. $2%(&g' ⇄ 2$%2&g' ". 7%2&g' ) $%2&g' ⇄ $%&g' ) 7%#&g'
5 eq < .# N !0?! 5 eq < (.2 N !0?( 5 eq < (. 5 eq <
13$ Consider the following equilibrium: $2&g' ) #2&g' ⇄ 2$#&g'
What is the final result of adding some $# gas to the s*stem at constant olume3 A. 5 eq increases. B. =2> decreases. C. =$#> decreases. ". 5 eq remains unchanged. 14$ Consider the following s*stem: 2C%&g' ) %2&g' ⇄ 2C%2&g'
A container is initiall* filled with C% and %2. ow will the =C%> and =C%2> change as the s*stem reaches equilibrium3
A. B. C. ".
=C%> ncrease ncrease "ecrease decrease
=C%2> "ecrease ncrease "ecrease increase
Answer 5e* %anuary 1999 7 C B 8 C 9 10 A " 11 12 C 13 C
&pril 1999 7 " C 8 C 9 10 A A 11 12 " 13 "
%une 1999 7 C C 8 C 9 10 A " 11 12 A 13 B
&u#ust 1999 7 A A 8 C 9 10 A A 11 12 B 13 A
