Kinetics

Question 1

What does the rate of a chemical reaction normally depend on

Answer 1

The rate of a chemical reaction normally depends on the concentrations of the reactants

Question 2

What are orders of reaction used to relate

Answer 2

Orders of reaction are used to relate the rate of a reaction to the reacting species

Question 3

What is the order of a reaction in which changing the concentration of a reactant has no effect on the rate

Answer 3

If changing the concentration of a reactant A has no effect on the rate of the reaction, then the reaction is zero order with respect to A.

Question 4

What is the order of a reaction that doubles the rate of the reaction as the concentration of reactants a doubled

Answer 4

If doubling the concentration of a reactant A doubles the rate of the reaction, then the reaction is first order with respect to A.

Question 5

How is the rate expressed

Answer 5

rate = k [A] where k is the rate constant and [A] is the concentration of reactant A in mol l-1

Question 6

What happens to the order of the reaction if doubling the concentration of the reactant increases the rate fourfold

Answer 6

If doubling the concentration of a reactant A increases the rate of the reaction fourfold, then the reaction is second order with respect to A

Question 7

How is second order expressed

Answer 7

Rate = k[A]^2

Question 8

What is the overall order of a reaction

Answer 8

The overall order of a reaction is the sum of the powers to which the concentrations of the reactants are raised in the rate equation.

Question 9

What can the order of a reaction only be determined by

Answer 9

The order of a reaction can only be determined from experimental data.

Question 10

How can the rate equation and rate constant be determined

Answer 10

The rate equation and the rate constant, including units, can be determined from initial rate data for a series of reactions in which the initial concentrations of reactants are varied. These can be zero, first, second or third order

Question 11

How do reactions usually occur

Answer 11

Reactions usually occur by a series of steps called a reaction mechanism.

Question 12

What is the rate of reaction dependant on

Answer 12

The rate of a reaction is dependant on the slowest step, which is called the rate determining step

Question 13

What can experimentally determined rate equations be used for

Answer 13

Experimentally determined rate equations can be used to determine possible reaction mechanisms