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 $mol \, s^{-1}$.

For the reaction ${N_2}_{(g)} + 3{H_2}_{(g)} \to 2N{H_3}_{(g)}$,what is the relationship between $\frac{d[N{H_3}]}{dt}$ and $-\frac{d[{H_2}]}{dt}$?

In the hydrolysis reaction of butyl chloride,the concentration of reactant at $600 \ s$ is determined using a tangent at $t_2 = 800 \ s$ and $t_1 = 400 \ s$. Given the concentrations $[R_2] = 0.0165 \ mol \ L^{-1}$ and $[R_1] = 0.037 \ mol \ L^{-1}$,calculate the instantaneous rate $r_{ins}$ at $600 \ s$.

In a reaction $A_2B_{3(g)} \to A_{2(g)} + \frac{3}{2}B_{2(g)}$,the pressure increases from $60 \ torr$ to $75 \ torr$ in $2.5 \ min$. The rate of disappearance of $A_2B_3$ is ........ $torr \cdot min^{-1}$.

For the reaction $5Br_{(aq)}^{-} + BrO_{3_{(aq)}}^{-} + 6H_{(aq)}^{+} \rightarrow 3Br_{2_{(aq)}} + 3H_{2}O_{(l)}$,if $\frac{-\Delta[Br^{-}]}{\Delta t} = 4.2 \times 10^{-3} \ mol \ L^{-1} \ s^{-1}$,calculate the rate of formation of $Br_{2}$,i.e.,$\frac{\Delta[Br_{2}]}{\Delta t}$.

Given above is the concentration vs time plot for a dissociation reaction: $A \rightarrow nB$. Based on the data of the initial phase of the reaction (initial $10 \ min$), the value of $n$ is . . . . . . .