Catalytic decomposition of hydrogen peroxide is a ........ order reaction.

The concentration of a substance undergoing a chemical reaction becomes one-half of its original value after time,regardless of the initial concentration. The reaction is an example of a

$A$ first order reaction is $50 \%$ complete in $16 \ min$. How much time is required to complete $87.5 \%$ of the reaction (in $min$)?

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:

The inactivation rate of a viral preparation is proportional to the amount of virus. In the first minute after preparation,$10 \%$ of the virus is inactivated. The rate constant for viral inactivation is $..... \times 10^{-3} \ min^{-1}$. (Nearest integer)
[Use : $\ln 10 = 2.303; \log_{10} 3 = 0.477; \text{property of logarithm} : \log x^y = y \log x$]

$A$ first order reaction takes $40 \ min$ for $20 \%$ decomposition. Calculate its rate constant.