The half-life of a first-order reaction is $20 \text{ minutes}$. What is the rate constant (in $\text{min}^{-1}$) for this reaction?

For a first order reaction,the concentration of reactant was reduced from $0.03 \ mol \ L^{-1}$ to $0.02 \ mol \ L^{-1}$ in $25 \ min$. What is its rate (in $mol \ L^{-1} \ s^{-1}$)?

In a first order reaction,the concentration of the reactant decreases from $20 \ mmol \ dm^{-3}$ to $8 \ mmol \ dm^{-3}$ in $40 \ minute$. Find the rate constant of the reaction.

If the half-life of a first-order reaction is $6.93$ minutes, then the time required for the completion of $99\%$ of the reaction will be . . . . . . minutes. (Given: $\log 2 = 0.3010$)

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

At $T(K)$,if the rate constant of a first order reaction is $4.606 \times 10^{-3} \ s^{-1}$,the time to reduce the initial concentration of the reactant to $1/10$ of its initial value in seconds is: