The decomposition of H2O2 in basic solution is first order in H2O2.
2H2O2(aq) → 2H2O2 (l) x O2(g)
the rate constant is 1.6 x 10–5 s–1 at 25°C and initial concentration of H2O2 is 0.20 M.
(a) What is the concentration of H2O2 after 2 hrs.
(b) How long will it take for H2O2 concentration to drop to 0.08 M.
(c) How long will it take for 90% of H2O2 to decompose?
Table 4.2. Integrated rate laws for the reactions of simpler order.
This reaction follows second order kinetics.
So that, the rate equation for this reaction will
Rate, R = k[X]2 .............(1)
Let initial concentration is x mol L−1,
Plug the value in equation (1)
Rate, R1 = k .(a)2
Given that concentration is increasing by 3 times so new concentration will 3a mol L−1
Plug the value in equation (1) we get
Rate, R2 = k (3a)2
We have already get that R1 = ka2 plus this value we get
R2 = 9 R1
So that, the rate of formation will increase by 9 times.
Rate = k[A]2
If concentration of X is increased to three times,
Rate = k[3A]2
or Rate = 9 k A2
Thus, rate will increase 9 times.