Question

The following reaction is second order in A and first order in B: 2A + B → 3C.
Determine the rate law for the reaction 4A + 2B→6C.

Answer 1

The rate law for the first reaction is

$$2A + B\rightarrow 3C$$

$$V = [A]^2[B]$$

We can see that in the second reaction the concentration of all species is doubled, then the rate law is:

$$4A + 2B \rightarrow 6C$$

$$V = [2A]^2[2B] = 2^2[A]^22[B]= 8[A]^2[B]$$

we can see then when we double the concentration of all species the rate of the reaction increases eight times.