CHEM 1128 Exam 2 Questions With
Verified Answers
⇌ t- tAnswer t- tIndicates tthat ta tprocess tis treversible t(forward tand treverse treactions)
Chemical tEquilibrium t- tAnswer t- tReactions twith tan tappreciable treverse treaction
-At tequilibrium tthe tamounts tof treactants tand tproducts tstop tchanging t
t
-No tfurther tchanges twill toccur tunless ttemperature tor tvolume tis tchanged
t
Forward tReaction t- tAnswer t- tReactants t→ tProducts
Reverse tReaction t- tAnswer t- tReactants t← tProducts
Rate tof tForward tReaction t- tAnswer t- tWill tstart tout tfast, tbut tas ttime tgoes ton tdecreasing tconcentration
tresults tin ta tdecreasing trate
Rate tof tReverse tReaction t- tAnswer t- tWill tstart tout tat t0 tor tslow, tbut tas ttime tgoes ton, tincreasing
tconcentration tresults tin tan tincreasing trate
Reaction tQuotient, tQ t- tAnswer t- tExpresses tamounts tof treactants tand tproducts tpresent tat tany tpoint tin ta
treversible treaction
The tConcentration tReaction tQuotient, tQ(c) t- tAnswer t- tExpresses tconcentrations tfrom tbalanced treaction
tin tMOLARITY
Q(c) tValue tChanges t- tAnswer t- t-Can tbe tcalculated tat tan tpoint tof tthe treaction t(including tinitial, t0), tbut
tthe tnumeric tvalue twill tvary tuntil tequilibrium tis testablished
-As tthe treaction tproceeds tthe tvalue twill tincrease tdue tto tincreased tproducts tand tdecreased treactants
t
-Value twill tno tlonger tchange tat tequilibrium
t
Law tof tMass tAction t- tAnswer t- tWhen ta treaction thas tachieved tequilibrium tat ta tgiven ttemperature, tthe
treaction tquotient talways thas tthe tsame tvalue
The tEquilibrium tConstant, tK t- tAnswer t- tThe tvalue tof tQ twhen tthe treaction tis tat tequilibrium
-Independent tof tstarting tconcentrations t
t
-Dependent ton ttemperature tand thow tthe treaction tis twritten t
t
-Magnitude tindicates tthe textent tof ta treaction, tnot tthe trate
t
Difference tbetween tQ tand tK t- tAnswer t- tK tconcentrations tmust tbe tat tequilibrium, twhile tQ tcan tbe tat tany
tpoint tof tthe treaction
, Coefficient tRule t- tAnswer t- tIf tthe tcoefficients tin ta tbalanced tequation tare tmultiplied tby ta tnumber, tn,
tthen tK tis traised tto tthe tnth tpower
Reciprocal tRule t- tAnswer t- tThe tequilibrium tconstants tfor tforward tand treverse treactions tare treciprocals
tof teach tother
Rule tof tMultiple tEquilibria t- tAnswer t- tIf ta treaction tcan tbe texpressed tas tthe tsum tof ttwo tor tmore
treactions, tthen tthe tK tvalue tfor tthe toverall treaction tis tthe tproduct tof tthe tK tvalues tof tthe tindividual
treactions t
K(R1) tx tK(R2) t= tK(R3) twhen tR1 t+ tR2 t= tR3
Equilibrium tConstant tMagnitude t- tAnswer t- t- tReactions tare tfeasible tas twritten tonly tif tK>>1 t(if tK tis tsmall
tthere twill tbe tno tappreciable tproduct tformation)
t -If tK tis tsmall: tThe tmixture tis tmostly treactants tat tequilibrium t
t -If tK tis tlarge: tThe tmixture tis tmostly tproducts tat tequilibrium t
t -If tK tis tintermediate: tAppreciable tamounts tof tboth tat tequilibrium
Direction tof tReaction t- tAnswer t- tA tsystem tnot tin tequilibrium twill tproceed tin tthe tdirection tto testablish
tequilibrium t
t t - When tQ t< tK: tShift ttoward tthe tproducts t
t t - When tQ t> tK: tShift ttoward tthe treactants t
t t - When tQ t= tK: tNo tshift, tequilibrium
Homogenous tEquilibrium t- tAnswer t- tAll treactants tin tproducts tare tin tthe tsame tphase t(most tcommon tin
tgaseous tor taqueous tphase)
Gaseous tChemical tEquilibria t- tAnswer t- tPartial tpressure tin tATM tcan tbe tused tin tQ tand tK texpressions
tbecause tthe tpartial tpressure tof ta tgas tis tdirectly tproportional tto tthe tconcentration
K(c) tand tK(p) t(Homogenous tEquilibrium) t- tAnswer t- tK(c) t= tEquilibrium tconstant tusing tconcentratoin t(M)
K(p) t= tEquilibrium tconstant tusing tpartial tpressure t(atm)
Δn(g) t- tAnswer t- tChange tin tnumber tof tmoles tof tgas t
t Δn(g) t= tn(g) tproducts t- tN(g) treactants
Heterogeneous tEquilibrium t- tAnswer t- tReactants tand tproducts tof treaction tmixture tare tin ttwo tor tmore
tdifferent tphases
t t - Pure tsolids tand tpure tliquids tdo tnot tappear tin tthe tK texpression t
- Position tof tequilibrium tis tindependent tof tthe tamount tof tsolid tor tliquid tpresent tas tlong tas tat tleast
t t
some tis tpresent tin tthe treaction tmixture
t
Verified Answers
⇌ t- tAnswer t- tIndicates tthat ta tprocess tis treversible t(forward tand treverse treactions)
Chemical tEquilibrium t- tAnswer t- tReactions twith tan tappreciable treverse treaction
-At tequilibrium tthe tamounts tof treactants tand tproducts tstop tchanging t
t
-No tfurther tchanges twill toccur tunless ttemperature tor tvolume tis tchanged
t
Forward tReaction t- tAnswer t- tReactants t→ tProducts
Reverse tReaction t- tAnswer t- tReactants t← tProducts
Rate tof tForward tReaction t- tAnswer t- tWill tstart tout tfast, tbut tas ttime tgoes ton tdecreasing tconcentration
tresults tin ta tdecreasing trate
Rate tof tReverse tReaction t- tAnswer t- tWill tstart tout tat t0 tor tslow, tbut tas ttime tgoes ton, tincreasing
tconcentration tresults tin tan tincreasing trate
Reaction tQuotient, tQ t- tAnswer t- tExpresses tamounts tof treactants tand tproducts tpresent tat tany tpoint tin ta
treversible treaction
The tConcentration tReaction tQuotient, tQ(c) t- tAnswer t- tExpresses tconcentrations tfrom tbalanced treaction
tin tMOLARITY
Q(c) tValue tChanges t- tAnswer t- t-Can tbe tcalculated tat tan tpoint tof tthe treaction t(including tinitial, t0), tbut
tthe tnumeric tvalue twill tvary tuntil tequilibrium tis testablished
-As tthe treaction tproceeds tthe tvalue twill tincrease tdue tto tincreased tproducts tand tdecreased treactants
t
-Value twill tno tlonger tchange tat tequilibrium
t
Law tof tMass tAction t- tAnswer t- tWhen ta treaction thas tachieved tequilibrium tat ta tgiven ttemperature, tthe
treaction tquotient talways thas tthe tsame tvalue
The tEquilibrium tConstant, tK t- tAnswer t- tThe tvalue tof tQ twhen tthe treaction tis tat tequilibrium
-Independent tof tstarting tconcentrations t
t
-Dependent ton ttemperature tand thow tthe treaction tis twritten t
t
-Magnitude tindicates tthe textent tof ta treaction, tnot tthe trate
t
Difference tbetween tQ tand tK t- tAnswer t- tK tconcentrations tmust tbe tat tequilibrium, twhile tQ tcan tbe tat tany
tpoint tof tthe treaction
, Coefficient tRule t- tAnswer t- tIf tthe tcoefficients tin ta tbalanced tequation tare tmultiplied tby ta tnumber, tn,
tthen tK tis traised tto tthe tnth tpower
Reciprocal tRule t- tAnswer t- tThe tequilibrium tconstants tfor tforward tand treverse treactions tare treciprocals
tof teach tother
Rule tof tMultiple tEquilibria t- tAnswer t- tIf ta treaction tcan tbe texpressed tas tthe tsum tof ttwo tor tmore
treactions, tthen tthe tK tvalue tfor tthe toverall treaction tis tthe tproduct tof tthe tK tvalues tof tthe tindividual
treactions t
K(R1) tx tK(R2) t= tK(R3) twhen tR1 t+ tR2 t= tR3
Equilibrium tConstant tMagnitude t- tAnswer t- t- tReactions tare tfeasible tas twritten tonly tif tK>>1 t(if tK tis tsmall
tthere twill tbe tno tappreciable tproduct tformation)
t -If tK tis tsmall: tThe tmixture tis tmostly treactants tat tequilibrium t
t -If tK tis tlarge: tThe tmixture tis tmostly tproducts tat tequilibrium t
t -If tK tis tintermediate: tAppreciable tamounts tof tboth tat tequilibrium
Direction tof tReaction t- tAnswer t- tA tsystem tnot tin tequilibrium twill tproceed tin tthe tdirection tto testablish
tequilibrium t
t t - When tQ t< tK: tShift ttoward tthe tproducts t
t t - When tQ t> tK: tShift ttoward tthe treactants t
t t - When tQ t= tK: tNo tshift, tequilibrium
Homogenous tEquilibrium t- tAnswer t- tAll treactants tin tproducts tare tin tthe tsame tphase t(most tcommon tin
tgaseous tor taqueous tphase)
Gaseous tChemical tEquilibria t- tAnswer t- tPartial tpressure tin tATM tcan tbe tused tin tQ tand tK texpressions
tbecause tthe tpartial tpressure tof ta tgas tis tdirectly tproportional tto tthe tconcentration
K(c) tand tK(p) t(Homogenous tEquilibrium) t- tAnswer t- tK(c) t= tEquilibrium tconstant tusing tconcentratoin t(M)
K(p) t= tEquilibrium tconstant tusing tpartial tpressure t(atm)
Δn(g) t- tAnswer t- tChange tin tnumber tof tmoles tof tgas t
t Δn(g) t= tn(g) tproducts t- tN(g) treactants
Heterogeneous tEquilibrium t- tAnswer t- tReactants tand tproducts tof treaction tmixture tare tin ttwo tor tmore
tdifferent tphases
t t - Pure tsolids tand tpure tliquids tdo tnot tappear tin tthe tK texpression t
- Position tof tequilibrium tis tindependent tof tthe tamount tof tsolid tor tliquid tpresent tas tlong tas tat tleast
t t
some tis tpresent tin tthe treaction tmixture
t
