AH Chemistry - Physical Chemistry - (c) - Kinetics

What does the rate of a chemical reaction normally depend on?

The rate of a chemical reaction normally depends on the concentration of the reactants.

What are orders of reaction used to do?

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

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

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.

If doubling the concentration of a reactant A doubles the rate of the reaction, then what order is the reaction with respect to A, and how can this be expressed?

If doubling the concentration of a reactant A doubles the rate of the reaction, then the reaction is first order with respect to A. This can be expressed as rate = k[A] where k is the rate constant and [A] is the concentration of reactant A in moll^-1.

If doubling the concentration of a reactant A increases the rate of the reaction fourfold, then what order is the reaction with respect to A, and how can this be expressed?

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. This can be expressed as rate = k[A]².

What is the order of a reaction with respect to any one reactant?

The order of a reaction with respect to any one reactant is the power to which the concentration of that reactant is raised in the rate equation.

What is the overall order of the reaction?

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

What is the only way the order of a reaction can be determined?

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

How do reactions usually occur?

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

What is the rate of reaction dependent on?

The rate of reaction is dependent on the slowest step, which is called the rate determining step.

What can experimentally determined rate equations be used to do?

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

What are the units of k for a reaction where the order is 0?

The units of k for a reaction where the order is 0 are moll^-1s^-1.

What are the units of k for a reaction where the order is 1?

The units of k for a reaction where the order is 1 are s^-1.

What are the units of k for a reaction where the order is 2?

The units of k for a reaction where the order is 2 are mol^-1ls^-1.

The units of k for a reaction where the order is 2 are mol^-2l²s^-1.