For a first order reaction,the velocity constant is $K = 10^{-3} \ s^{-1}$. The two-third life for it would be ........... $s$.

Calculate the rate constant of the first order reaction if $20 \%$ of the reactant decomposes in $15 \ minutes$.

Half life of a first order reaction is $20 \ min$. The time taken to reduce the initial concentration of reactant to $(1/10)^{th}$ is $\qquad$ (in $min$)

For the first order reaction $A \rightarrow B$,the half-life is $30 \ min$. The time taken for $75 \%$ completion of the reaction is $..... \ min$. (Nearest integer)
Given: $\log 2 = 0.3010, \log 3 = 0.4771, \log 5 = 0.6989$

The reaction $A + B \xrightarrow{k}$ product is first order with respect to $A$ and zero order with respect to $B$. If $a_0$ and $a_t$ are the concentrations of $A$ at $t = 0$ and after time $t \, sec$ respectively,then select the correct relationship -

For a first-order reaction,the rate constant is $3 \times 10^{-6} \, s^{-1}$. If the initial concentration is $0.10 \, M$,the initial rate is.........