Question

In a reaction A+B -> product, rate is doubled when the concentration of B is doubled and rate increases by a factor of 8 when the concentration of both the reactants A and B are doubled, rate law for the reaction can be written as?

Answer 1

`rate = k[A]^1[B]^3]`

Explanation:

We're working with rate constants, so this is where we need to know our orders

Zeroth order means there is no change in rate when conc is changes

First order means there is a direct proportional relationship, I.E when A is doubled, rate doubles too

Second order means there is a square relationship, therefore when A doubles, rate multiplies `2^2` which is 4

Third order means there is a cubic relationship, therefore when A doubles, rate multiplies by `2^3` which is 8

The order represents the power above each reactant therefore:

`rate = k[A]^1[B]^3]`