For the $1^{st}$ order reaction,the half-life is $5 \ minutes$ when $[A] = 0.1 \ M$. If the concentration of $[A]$ becomes twice,then the half-life becomes:

The half-life period of a first order reaction is $100 \, \text{sec}$. The rate constant of the reaction is

$A$ first order reaction is found to have a rate constant,$k = 5.5 \times 10^{-14} \ s^{-1}$. The half life of reaction is . . . . . . .

The rate constant for the decomposition of $H_2O_2$ is $3.66 \times 10^{-3} \ s^{-1}$. If the initial concentration of $H_2O_2$ is $0.882 \ M$,then in how many seconds will its concentration become $0.600 \ M$?

If $75 \%$ of a first order reaction was completed in $90 \ minutes$,$60 \%$ of the same reaction would be completed in approximately (in minutes)..........
(Take: $\log 2=0.30 ; \log 2.5=0.40)$

$A$ flask contains a mixture of compounds $AB$ and $XY$. Both decompose by first-order kinetics upon heating. If the half-life periods of $AB$ and $XY$ are $30 \ min$ and $10 \ min$ respectively,how many minutes will it take for the concentration of $AB$ to be four times the concentration of $XY$? (Assume initial concentrations of $AB$ and $XY$ are equal.)