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 $3.0 \ g$?

Rate of first order reaction $A \rightarrow \text{product}$ is $0.01 \ mol \ dm^{-3} \ s^{-1}$. Calculate the rate constant if the concentration of the reactant is $0.2 \ M$. (in $s^{-1}$)

For the decomposition of $N_2O_5$ according to the equation $2N_2O_5(g) \to 4NO_2(g) + O_2(g)$,the reaction is of first order. After $30 \, \min$ from the start of the reaction in a closed vessel,the total pressure is $305.5 \, mm \, Hg$,and at the end of complete decomposition,the total pressure is $587.5 \, mm \, Hg$. Calculate the rate constant of the reaction.

For the given first order reaction $A \rightarrow B$,the half-life of the reaction is $0.3010 \ min$. The ratio of the initial concentration of reactant to the concentration of reactant at time $2.0 \ min$ will be equal to $........$ (Nearest integer).

The following data were obtained during the first order thermal decomposition of $SO_{2}Cl_{2}$ at a constant volume.
$SO_{2}Cl_{2(g)} \to SO_{2(g)} + Cl_{2(g)}$

Experiment	Time $/$ $s$	Total pressure $/$ $atm$
$1$	$0$	$0.5$
$2$	$100$	$0.6$

Calculate the rate of the reaction when total pressure is $0.65 \ atm$.

The reaction $X \rightarrow$ products is a first order reaction. In $40 \ min$,the concentration of $X$ changes from $1.0 \ M$ to $0.25 \ M$. What is the rate of reaction when $[X] = 0.1 \ M$? $(\log 4 = 0.60)$