For the reaction,

                             A $\to$ Products (order = n),

the time of completion of reaction is-

nth order reaction,

$V_{in}t=\frac{1}{(n-1)}\left\{\frac{1}{{\left([A{]}_0-x\right)}^{n-1}}-\frac{1}{[A{]}_0^{n-1}}\right\}$

For the n=-1, the time of completion of reaction will be infinite.

When the value of n is negative or equal to zero, then time

$=\frac{{\left[A_0\right]}^{1-n}}{K(1-n)}$