For the first order reaction with rate contant `k`, which expression gives the half life period ? (Initail conc. = a)

For a first order reaction with rate constant 'k' and initial concentration 'a', the half-life period is given by

For a first order reaction with rate constant 'k' and initial concentration 'a', the half-life period is given by

For a first order reaction with rate constant 'k' and initial concentration 'a', the half-life period is given by

For a first order reaction, the half-life period is

A first order reaction has rate constant of 10^(-2) (sec)^(-1) . Calculate the half life period for this reaction.

The half-life period of a certain reaction is directly proportional to initial concentration of the reactant. Predict the order of the reaction and white the expression to calculate the half-life period of the reaction.