Question

The rate constant for the decomposition reaction of H2O2 is 3.66 × 10−3 s−1 at a particular temperature. What is the concentration of H2O2 in a solution that was initially 10.0 M H2O2 after 15.0 minutes have passed?

Answer 1

Answer: 3.72 M

Step-by-step explanation:

Expression for rate law for first order kinetics is given by:

`t=(2.303)/(k)\log(a)/(a-x)`

where,

k = rate constant =
`3.66* 10^(-3)s^(-1)`

t = age of sample = 15.0 minutes

a = let initial amount of the reactant = 10.0 M

a - x = amount left after decay process = ?

`15.0* 60s=(2.303)/(3.66* 10^(-3))\log(10.0)/((a-x))`

`\log(100)/((a-x))=1.43`

`(100)/((a-x))=26.9`

`(a-x)=3.72M`

The concentration of
`H_2O_2` in a solution after 15.0 minutes have passed is 3.72 M