Chapter 13

Question 1

What is chemical kinetics?

Answer 1

This is the study of the rates of change of concentrations of substances involved in chemical reactions.

Question 2

What is a reaction rate? What values are used in this measurement?

Answer 2

This is a measure of how rapidly a reaction occurs. This is expressed in concentration/time.

Question 3

In the following reaction:

aA + bB → cC

How do we relate the rates of formation of the reactants and products, assuming a, b, and c are coefficients.

Answer 3

-1/a(Δ[A]/Δt) = -1/b(Δ[B]/Δt) = 1/c(Δ[C]/Δt)

Question 4

What is reaction order?

Answer 4

This is an experimentally determined number defining the dependence of the reaction rate on the concentration of a reactant.

Question 5

What is the rate constant?

Answer 5

This is the porportionality constant that relates the rates of reaction to the concentration of reaction. (Often expressed as k)

Question 6

What is the rate law?

Answer 6

This is an equation that that defines the experimentally determined relation between the concentration of reactants in a chemical reaction and the rate of that reaction.

ex.) k[O₃][NO]

Question 7

What is overall reaction order?

Answer 7

The sum of the powers in a rate law.

ex.) k[O₃][NO] - the overall reaction order would be 2

Question 8

How do we calculate k, given the initial reaction rates and initial molarities?

Answer 8

rate = k[A][B] = x M/s

Then solve for k given your known A and B values multiplied together.