Question

Explain half life method for determination of order of reaction.

Answer 1

In this method initial rate of reaction is determined by varying the concentration of one of the reactants while others are kept constant

R = k[A]x[B]y[C]z

if [B] & [C] = Constant

then for two different initial concentrations of A we have

R_{0_1} = k[A_0]^{a}_{1}

and

R_{0_2} = k[A_0]^{a}_{2}

\Rightarrow \frac{R_{0_1}}{R_{0_2}} = (\frac{[A_0]_1}{[A_0]_2})^n