Which of the following units is used to express the rate of a reaction?

For the reaction $R \rightarrow P$,the concentration of a reactant changes from $0.03 \, M$ to $0.02 \, M$ in $25 \, minutes$. Calculate the average rate of reaction using units of time both in $minutes$ and $seconds$.

For the reaction $3A \to 2B$,the rate of reaction is expressed as $\frac{+d[B]}{dt} = \dots$

In the hydrogenation of ethene at $298 \, K$,the number of moles of hydrogen decreases from $2.2$ to $1.4$ in $50 \, min$. Calculate the rate of reaction in units of $mol \, s^{-1}$.

Which of the following equations is correct regarding the rate of disappearance of reactant and appearance of product for the reaction $N_{2(g)} + 3H_{2(g)} \rightarrow 2NH_{3(g)}$?

Consider the following reaction: $N_{2(g)} + 3H_{2(g)} \longrightarrow 2NH_{3(g)}$. The rate of this reaction in terms of $N_2$ at $T \ K$ is $\frac{-d[N_2]}{dt} = 0.02 \ mol \ L^{-1} \ s^{-1}$. What is the value of $\frac{-d[H_2]}{dt}$ (in units of $mol \ L^{-1} \ s^{-1}$) at the same temperature?