Question

The half-life for the second-order decomposition of HI is 15.4 s when the initial concentration of HI is 0.67 M. What is the rate constant for this reaction? A) 1.0 * 10-2 M-15-1 B) 4.5 * 10-2 M-15-1 C) 9.7* 10-2 M-15-1 OD) 2.2 * 10-2 M-15-1

Answer 1

The correct answer is option C.

Step-by-step explanation:

Half life for second order kinetics is given by:

`t_{(1)/(2)=(1)/(k* A_0)`

`t_{(1)/(2)` = half life = 15.4 s

k = rate constant =?

`A_0` = initial concentration = 0.67 M

`15.4 s=(1)/(k* 0.67 M)`

`k=(1)/(15.4 s* 0.67 M)=0.09692 M^(-1) s^(-1)=9.69* 10^(-2)M^(-1) s^(-1)\approx 9.7* 10^(-2) M^(-1) s^(-1)`

`9.7* 10^(-2) M^(-1) s^(-1)` is the rate constant for this reaction.