The first order reaction takes $20 \ min$ to complete $15\%$. How much time is required to complete $75\%$ of the reaction (in $min$)?

If the rate constant for a first order reaction is $k$,then find the time required for completion of $80 \%$ of the reaction.

If the time required for $90\%$ completion of a first-order reaction is '$t$', what is the time required for $99.9\%$ completion of the reaction at the same temperature?

$A$ first order reaction has a rate constant of $2.303 \times 10^{-3} \; s^{-1}$. The time required for $40 \; g$ of this reactant to reduce to $10 \; g$ will be.....$s$
[Given that $\log_{10} 2 = 0.3010$]

Time required for $90 \%$ completion of a first order reaction is '$x$' minute. Calculate the time required to complete $99.9 \%$ of the reaction at the same temperature.

For the thermal decomposition of $N_2O_{5(g)}$ at constant volume,the following table can be formed for the reaction mentioned below:
$2N_2O_{5(g)} \rightarrow 2N_2O_{4(g)} + O_{2(g)}$

$S.NO$	$Time/s$	Total pressure $(atm)$
$1.$	$0$	$0.6$
$2.$	$100$	$X$

$X = . . . . . . \times 10^{-3} \ atm$ [nearest integer]
Given: Rate constant for the reaction is $4.606 \times 10^{-2} \ s^{-1}$.