In a first order decomposition reaction,the time taken for the decomposition of reactant to one fourth and one eighth of its initial concentration are $t_1$ and $t_2 \ s$,respectively. The ratio $t_1 / t_2$ will be:

If $50\%$ of a reaction occurs in $100 \ s$ and $75\%$ of the reaction occurs in $200 \ s$,the order of this reaction is

For the first order reaction $2 N_2O_{5(g)} \rightarrow 4 NO_{2(g)} + O_{2(g)}$,which of the following statements are correct?
$A.$ The concentration of the reactant decreases exponentially with time.
$B.$ The half-life of the reaction decreases with increasing temperature.
$C.$ The half-life of the reaction depends on the initial concentration of the reactant.
$D.$ The reaction proceeds to $99.6 \%$ completion in eight half-life durations.

For a first order reaction $A \to B$,the reaction rate at reactant concentration of $0.01 \ M$ is found to be $2.0 \times 10^{-5} \ M \ sec^{-1}$. The half-life period of the reaction is .......... $sec$.

Hydrolysis of $DDT$ is a first order reaction,its half-life is $10 \ years$. Time required to hydrolyse $10 \ g$ of $DDT$ to half is ......... $years$.

For a first-order reaction $A \to B$,the rate of reaction at a reactant concentration of $0.01 \, M$ is $2.0 \times 10^{-5} \, mol \, L^{-1} \, s^{-1}$. The half-life period of the reaction is .... $s$.