Kinetics

Question 1

Increase in temp makes the rate …

Answer 1

go faster

Question 2

Addition of a catalyst makes the rate …

Answer 2

go faster

Question 3

Increase in pressure makes the rate …

Answer 3

go faster

Question 4

Increase in concentration makes the rate …

Answer 4

go faster

Question 5

Reaction Rate

Answer 5

a positive quantity that tells us how the concentration of a reactant or product changes with time

Question 6

Rate over time

Answer 6

changes over time as concentrations of reactants and products change

Question 7

Instantaneous rate of change

Answer 7

slope of the tangent line of a point on the concentration curve

Question 8

Average rate of change

Answer 8

shows how products change over time (rate=-dconc./dt)

Question 9

Rate law

Answer 9

rate expression shows how rate changes as concentration changes (rate = k[A]^n)

Question 10

Higher temperature means …

Answer 10

faster rate

Question 11

Lower temperature means …

Answer 11

slower rate

Question 12

Rate doubles with …

Answer 12

a ten degree increase

Question 13

rate and temperature have a …

Answer 13

direct relationship

Question 14

Arrhenius equation

Answer 14

lnk = A - Ea/RT or lnk2/k1 = Ea/RT((T2-T1)/T2T1)

Question 15

O order integrated rate law

Answer 15

Ao - A = kt

Question 16

1st order integrated rate law

Answer 16

lnA = lnAo - kt

Question 17

2nd order integrated rate law

Answer 17

kt = 1/A - 1/Ao

Question 18

Half life equation 0 order

Answer 18

Ao/2k = t1/2

Question 19

Half life equation 1st order

Answer 19

.693/k = t1/2

Question 20

Half life equation 2nd order

Answer 20

1/(k[A]o) = t1/2

Question 21

Catalysis

Answer 21

a catalyst increases the rate of a reaction without being consumed by the reaction

Question 22

Heterogeneous catalysis

Answer 22

• in a different phase from the reaction mixture
• most commonly a solid that increases the rate of a liquid or gas mixture

Question 23

Homogeneous catalysis

Answer 23

• in the same phase as the reaction mixture
• speeds up the reaction by forming a reactive intermediate that decomposes to give products
• provides an alternative path of lower activation energy

Question 24

Reaction Mechanisms

Answer 24

• a description of a path or a sequence of steps that show how the reaction might occur
• the slow step is rate determining
• overall rate of the reaction cannot exceed that of the slowest step
• if the slowest step is by far the slowest, its rate will be approximately equal to that of the whole reaction

Question 25

Deducing a rate expression from a proposed mechanism

Answer 25

• find the slowest step and equate the rate of the overall reaction to the rate of that step
• find the rate expression for the slowest step
• the final rate expression must include only the species that appear in the balanced equation for the overall reaction