1. Orders, rate equations and rate constants

Question 1

definition

rate of reaction

Answer 1

the change in concentration of a reactant or product per unit of time

Question 2

definition  
rate constant (k)

Answer 2

constant that links the rate of reaction with the concentration of the reactants raised to the power of their orders in the rate equation

Question 3

definition

the rate equation

Answer 3

A+B->C =

rate = k [A]m[B}n

Question 4

definition

the overall order

Answer 4

sum of individual orders of a reaction

m+n

Question 5

how to calculate rate of reaction

Answer 5

rate of reaction= change in conc of reaction or product / time

Question 6

what are the usual units of rate of reaction

Answer 6

moldm-3 s-1

Question 7

3 main types of order

Answer 7

1st order
2nd order
0 order

Question 8

zero order
order is 0 with respect to A
rate ∝ [A]0

Answer 8

rate unaffected by change in concentration
any number to power of 0 = 1
does not appear in rate equation (doesn’t affect rate)

Question 9

first order
order is 1 with respect to B
rate ∝ [B]1

Answer 9

rate directly proportional to the concentration
if [B] increases 2 times rate increases 2 times
if [B] increases 3 times rate increases 3 times

Question 10

second order
order is 2 with respect to C
rate ∝ [C]2

Answer 10

change in rate equal to change in conc squared
if [C] increases by 2 times rate increases by 2 squared = 4 times
if [C] increases by 3 times rate increases by 3 squared = 9 times