15-4

1. For the first order reaction A + B --à C, the initial concentration of A is 0.26M, how long it must take for the concentration of A to reduce to 0.176M? k=0.33min^-1

2. If the initial concentration of the reactant of a first order reaction is 0.135M, what is the concentration after 1.5s. k=0.75s^-1

3. The rate constant for a second-order reaction is 0.26M^-1s^-1, if the initial concentration of reactant is 0.26M, how long it must take for the concentration to drop to 0.13M?

4. What is the rate constant of a first order reaction that has a half-life of 144s?

5. A reaction is in first order of the reactant A. A solution initially has 0.120M of A is found to have 0.015M after 54 min. What is the half-life?