CHM001B WS14:ChemicalKinetics

MissionCollege1|P a g e

Name______________________________ Date______________ Grade______________

Q1.Considerthereaction:

2𝑁!𝑂 𝑔 → 2𝑁! 𝑔 + 𝑂!(𝑔)

a. Expresstherateofthereactionintermsofthechangeinconcentrationofeachofthereactantsandproducts.

b. Inthefirst15.0softhereaction,0.015molofoxygengasisproducedinareactionvesselwithavolumeof0.500L.Whatistheaveragerateofthereaction(inM/s)duringthistimeinterval?

c. Predicttherateofchangeintheconcentrationofdinitrogenmonoxide(inM/s)duringthistimeinterval.

CHM001B WS14:ChemicalKinetics

MissionCollege2|P a g e

Q2.Considerthereaction:

𝑁𝑂! 𝑔 → 𝑁𝑂 𝑔 + 12𝑂!(𝑔)

Thedatabelowwascollectedfortheconcentrationofnitrogendioxideasafunctionoftime:

Times (s) [NO2] (M)

0 1.00010 0.95120 0.90430 0.86040 0.81850 0.77860 0.74070 0.70480 0.67090 0.637

100 0.606

a. Whatistheaveragerateofreaction(inM/s)between10and20s?Between50and60s?

b. Whatistherateofformationofoxygengas(inM/s)between50and60s?

CHM001B WS14:ChemicalKinetics

MissionCollege3|P a g e

Q3.Whataretheunitsofkforeachtypeofreaction?Showyourwork.

a. zero-orderreaction

b. first-orderreaction

c. second-orderreaction

Q4.Thereactionisfirstorderwithrespecttodinitrogenpentaoxide:

𝑁!𝑂! 𝑔 → 𝑁𝑂! 𝑔 + 𝑁𝑂!(𝑔)

Therateconstantforthereactionatacertaintemperatureif0.053s-1.

a. Calculatetherateofthereaction(inM/s)whentheconcentrationofdinitrogenmonoxideis0.055M.

b. Whatistherateofthereaction(inM/s)attheconcentrationindicatedinpartaifthereactionissecondorder?(Assumethesamenumericalvaluefortherateconstantwiththeappropriateunits.)

CHM001B WS14:ChemicalKinetics

MissionCollege4|P a g e

Q5.Considerthereactionanddatabelow:

𝐶𝐻!𝐶𝑙 𝑔 + 3𝐶𝑙! 𝑔 → 𝐶𝐶𝑙! 𝑔 + 3𝐻𝐶𝑙(𝑔)

[CH 3Cl] (M) [Cl2] (M) In it ia l rate (M/s)

0.050 0.050 0.0140.100 0.050 0.0290.100 0.100 0.0410.200 0.200 0.115

a. Whatistheratelawforthereaction?

b. Calculatethevalueoftherateconstant.

c. Whatistheoverallorderofthereaction?

CHM001B WS14:ChemicalKinetics

MissionCollege5|P a g e

Q6.Answerthefollowingquestionsbasedonthedataprovided:

𝑁!𝑂! 𝑔 → 𝑁𝑂! 𝑔 + 𝑁𝑂!(𝑔)

Time (s) [N2O5] (M)

0 1.00025 0.82250 0.67775 0.557

100 0.458125 0.377150 0.310175 0.255200 0.210

a. Whatistheoverallorderofthereaction?

b. Calculatethevalueoftherateconstant.

c. Whatistheconcentrationofdinitrogenmonoxideat250s?

CHM001B WS14:ChemicalKinetics

MissionCollege6|P a g e

Q7.Thisreactionwasmonitoredasafunctionoftime:

𝐴𝐵 → 𝐴 + 𝐵

Aplotof ![!"]

versustimeyieldsastraightlinewithslope-0.055M/s.

a. Whatisthevalueoftherateconstantforthisreaction?

b. Writetheratelawforthereaction.

c. Whatisthehalf-lifewhentheinitialconcentrationis0.55M?

d. IftheinitialconcentrationofABis0.250M,andthereactionmixtureinitiallycontainsnoproducts,whataretheconcentrationsofAandBafter75s?

CHM001B WS14:ChemicalKinetics

MissionCollege7|P a g e

Q8.Thehalf-lifefortheradioactivedecayofC-14is5730yearsandisindependentofinitialconcentration.Howlongdoesittakefor25%oftheC-14atomsinasampleofC-14todecay?IfasampleofC-14initiallycontains1.5mmolofC-14,howmanymillimolesareleftafter2255years?

Q9.Achemicalreactionisendothermicandhasanactivationenergythatistwicethevalueoftheenthalpychangeofthereaction.Drawadiagramdepictingtheenergyofthereactionasitprogresses.Labelthepositionofthereactantsandproductsandindicatetheactivationenergyandenthalpyofreaction.

Q10.Therateconstantofareactionat32°Cis0.055s-1.Ifthefrequencyfactoris1.2x1013s-1,whatistheactivationbarrier(inkJ/mol)?

CHM001B WS14:ChemicalKinetics

MissionCollege8|P a g e

Q11.UseanArrheniusplottodeterminetheactivationbarrier(inkJ/mol)andfrequencyfactor(ins-1)forthereaction.

Temperature (K) Rate constant (s-1)

300 0.0134310 0.0407320 0.114330 0.303340 0.757

Q12.Areactionhasarateconstantof0.000122s-1at27°Cand0.228s-1at77°C.

a. Determinetheactivationbarrierforthereaction.

b. Whatisthevalueoftherateconstantat17°C?

CHM001B WS14:ChemicalKinetics

MissionCollege9|P a g e

Q13.Considerthistwo-stepmechanismforareaction:

𝑁𝑂! 𝑔 + 𝐶𝑙! 𝑔 !! 𝐶𝑙𝑁𝑂! 𝑔 + 𝐶𝑙 𝑔 𝑆𝑙𝑜𝑤

𝑁𝑂! 𝑔 + 𝐶𝑙 𝑔!!

𝐶𝑙𝑁𝑂! 𝑔 𝐹𝑎𝑠𝑡

a. Whatistheoverallreaction?

b. Identifytheintermediatesinthemechanism.

c. Whatisthepredictedratelaw?