The order of reaction is defined as the sum of the powers of concentrations In the rate law.
The rate of second order reaction can be expressed as rate = k[A]2
The reaction X → Y follows second order kinetics.
Therefore, the rate equation for this reaction will be:
Rate = k[X]2 ________________________ (1)
Let [X] = a mol L-1 , then equation (1) can be written as:
Rate = k [a]2
= ka2
If the concentration of X is increased to three times, then [X] = 3a mol L-1
Now, the rate equation will be:
Rate = k [3a]2
= 9(ka2)
Hence, the rate of formation will increase by 9 times.