5.2 Introduction to Rate Law

What can experimental methods be used to determine?

Rate of a reaction

How can experimental methods be used to determine the rate of a reaction?

By monitoring the amounts of reactants and/or products of a reaction

How does the rate law express the rate of a reaction?

Proportional to the concentration of each reactant raised to a power

What is the power of each reactant in the rate law equal to?

The order of the reaction with respect to that reactant

What is the sum of the powers of the reactant concentrations in the rate law equal to?

Overall order of the reaction

What is the proportionality constant int he rate law called?

Rate constant

What is the value of the rate constant dependent on?

Temperature

What do the units of the rate constant reflect?

The overall reaction order

What is a method to determine the order with respect to each reactant?

Investigate how changes in the initial concentration of reactants affect initial reaction rate

What kind of value is the order with respect to a certain reactant?

Numerical value

What number is the order with respect to a certain reactant usually?

0,1,2

What is the order with respect to a certain reactant determined by?

Experimental data

What does the order with respect to a certain reactant in a chemical reaction indicate?

How the change in the initial concentration of that reactant will affect the initial reaction rate

Can the order with respect to a certain reactant be the same as the coefficient of that reactant in the overall balanced chemical equation?

Yes

Is the order with respect to a certain reactant always the same as the coefficient of that reactant in the overall balanced chemical equation?

Not always

Why must the order with respect to a certain reactant be determined from experimental data?

It is not always the same as the coefficient of that reactant in the overall balanced chemical equation

What can the value of the rate constant be calculated from?

Experimental data

What is k?

Value of rate constant

Is the value of k always the same for all chemical reactions?

No

What is the rate constant dependent on?

Temperature at which the reaction is carried out

What causes the value of the rate constant to change?

Changing the initial temperature at which the reaction is performed

How does changing the initial concentrations of the reactants affect the rate constant?

No change

If a reaction is zero order with respect to A, if the initial value of [A] is doubled, the initial reaction rate will:

Stay the same

If a reaction is first order with respect to A, if the initial value of [A] is doubled, the initial reaction rate will:

Double

If a reaction is second order with respect to A, if the initial value of [A] is doubled, the initial reaction rate will:

Quadruple