From the data given below, show that the decomposition of hydrogen peroxide in aqueous solution is a first order reaction:.
Time (min) 0 10 20
N (mL) 22.8 13.8 8.20
where N is the volume of standard potassium permanganate solution in mL required to decompose definite volume of the peroxide solution.
The volume of standard KMnO4 is proportional to the amount of H2O2. It can therefore be used in place of concentration of H,O2.
So,
[A]0 = 22.8 mL,
[A]10 min = 13.8 mL
[A]20 min = 8.20 mL
Substituting the values of concentration and time in the first order rate equation
(i)
(ii)
Since k has the same value in both cases, decomposition of hydrogen peroxide is a first order reaction.
130 Views