( ii) Initial rate method In this method, the order of a reaction is determined by varying the concentration of one of the
Reactants while others are kept constant.
( ii) Integrated rate law method In this method out different integrated rate equation which gives the most constant value for the rate constant corresponds to a specific order of reaction.
( iii) Half-life period( t 1 / 2) method In general half-life period( t 1 / 2) of a reaction of nth order is related to initial concentration of the reactant as
This method is employed only when the rate law involved only one concentration term.
( v) Ostwald’ s isolation method This method is employed in determining the order of complicated reactions by isolating one of the reactants so far as its influence on the reaction rate is concerned.
Temperature Dependence of Rate of a Reaction
For every 10 ° C rise in temperature, the rate of reaction becomes double, but only 16 % collisions increases. It can be explained by Arrhenius equation.
Temperature coefficient is the ratio of rate constant of a reaction at two temperature differing by 10. Temperature selected are usually 298 K and 308 K
Temperature coefficient = Rt + 10 / Rt ≈ 2 to 3