The rate constant of a first-order reaction is $1.20 \times 10^{-3} \, s^{-1}$. How much time will it take for $5 \, g$ of the reactant to reduce to $3 \, g$ (in $, s$)?

The half-life values for two different first-order reactions $A$ and $B$ are $75 \ min$ and $2.5 \ h$ respectively. What is the ratio of their rate constants $\frac{k_A}{k_B}$?

For the first-order isomerization reaction $A \rightarrow B$,the rate constant is $4.5 \times 10^{-3} \ min^{-1}$. If the initial concentration of $A$ is $1 \ M$,find the rate of the reaction after $1 \ hour$.

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 .... $s$.

The rate constant of a first order reaction is $15 \times 10^{-3} \ s^{-1}$. How many seconds will $5.0 \ g$ of this reactant take to reduce to $3.0 \ g$?

For a first-order reaction involving gaseous reactants and gaseous products,what will be the unit of its rate constant?