If the half-life $(t_{1/2})$ of a first-order reaction is $20 \ minutes$,what fraction of the reactant remains after $40 \ minutes$?

An organic compound undergoes first order decomposition. If the time taken for the $60 \%$ decomposition is $540 \ s$,then the time required for $90 \%$ decomposition will be $.......... \ s$. (Nearest integer). Given : $\ln 10 = 2.3 ; \log 2 = 0.3$

What is the time required for $75 \%$ completion of a first order reaction if the rate constant is $23.03 \text{ minute}^{-1}$ (in $\text{ s}$)?

Given: $2A \rightarrow B$. The rate constant of the reaction is $K = 10^{-2} \ min^{-1}$. Which statement is correct? $(\ln 2 = 0.7)$

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

Mathematical representation for $t_{1/4}$ life for a first-order reaction is given by: