Calculate the time required for 25% completion of a 1 order reaction whose rate constant is 0.015`min^(-1)`.

The time required for 100% completion of a zero order reaction is

For first order reaction, rate constant :

Calculate the half-life period of a first order reaction if rate constant is 0.45 mi n^(_1) .

The half life period of a first order chemical reaction is 6.93 minutes . The time required for the completion of 99% of the chemical reaction will be ( log 2 = 0.301 ) :