Question

By what factor will the rate of the reaction change if the ph decreases from 6.00 to 2.00? express your answer numerically using two significant figures. view available hint(s)

Answer 1

The reaction equation is first order with respect to [H+]

when PH1 = -㏒[H+]1  so, when PH = 6

So by substitution:

∴ 6 = -㏒[H+]1

∴[H+]1 = 1 x 10^-6

and when PH2 = -㏒[H+]2 so, when PH2 = 2

so by substitution:

∴ 2 = -㏒[H]2

∴[H]2 = 1 x 10^-2

So the rate of reaction changes by the factor of:

[H2]2/[H]1 = (1 x 10^-2) / (1 x 10^-6) = 10000

It is 10000 times faster when PH decreases from 6 to 2