Half-life period of a first-order reaction is $10 \ min$. Starting with an initial concentration of $12 \ M$,the rate after $20 \ min$ is:

The reaction $2N_2O_5 \,(g) \to 4NO_2 \,(g) + O_2 \,(g)$ follows first order kinetics. The pressure of a vessel containing only $N_2O_5$ was found to increase from $50 \, mmHg$ to $87.5 \, mmHg$ in $30 \, min$. The pressure exerted by the gases after $60 \, min$ will be .......... $mmHg$ (assume temperature remains constant).

Gaseous cyclobutene isomerizes to butadiene in a first order process which has a $k$ value of $3.3 \times 10^{-4} \ s^{-1}$ at $153^{\circ}C$. The time in minutes it takes for the isomerization to proceed $40\%$ to completion at this temperature is ..........
(Rounded off to the nearest integer)

If the half-life period of a first order reaction is $138.6 \ minutes$,then the value of the decay constant for the reaction will be:

For a first-order reaction,it takes $20 \, \text{min}$ for the concentration to decrease from $1 \, M$ to $0.6 \, M$. How much time is required for the concentration to decrease from $0.6 \, M$ to $0.36 \, M$?

For a first order reaction,the graph between $\log \frac{a}{(a-x)}$ (on $y$-axis) and time (in $min$,on $x$-axis) gave a straight line passing through origin. The slope is $2 \times 10^{-3} \ min^{-1}$. What is the rate constant (in $min^{-1}$)?