For the reaction $N_2 + 3H_2 \to 2NH_3$,if $\frac{\Delta [NH_3]}{\Delta t} = 2 \times 10^{-4} \ mol \ L^{-1} s^{-1}$,the value of $\frac{-\Delta [H_2]}{\Delta t}$ would be

For the chemical reaction: $N_{2(g)} + 3H_{2(g)} \rightarrow 2NH_{3(g)}$,the rate of reaction can be expressed in terms of the concentration of $N_{2(g)}$,$H_{2(g)}$,or $NH_{3(g)}$ with respect to time. Identify the correct relationship between these rates.

For the reaction $I_2 + 2S_2O_3^{2-} \rightarrow 2I^{-} + S_4O_6^{2-}$,which of the following expressions correctly represents the rate of reaction?

The reaction that occurs in a breath analyser,a device used to determine the alcohol level in a person's blood stream is $2 K_{2}Cr_{2}O_{7} + 8 H_{2}SO_{4} + 3 C_{2}H_{6}O$ $\rightarrow 2 Cr_{2}(SO_{4})_{3} + 3 C_{2}H_{4}O_{2} + 2 K_{2}SO_{4} + 11 H_{2}O$. If the rate of appearance of $Cr_{2}(SO_{4})_{3}$ is $2.67 \ mol \ min^{-1}$ at a particular time,the rate of disappearance of $C_{2}H_{6}O$ at the same time is ...... $mol \ min^{-1}$ (Nearest integer).

For the reaction $2A + B \rightarrow 2C$,the rate of disappearance of $A$ is $0.076 \ mol \ s^{-1}$. What is the rate of disappearance of $B$?

$NO_2$ required for a reaction is produced by the decomposition of $N_2O_5$ in $CCl_4$ as per the equation $2N_2O_{5(g)} \to 4NO_{2(g)} + O_{2(g)}$. The initial concentration of $N_2O_5$ is $3.00 \, mol \, L^{-1}$ and it is $2.75 \, mol \, L^{-1}$ after $30 \, minutes$. The rate of formation of $NO_2$ is ............... $mol \, L^{-1} \, min^{-1}$