Match List I with List II : List-I (Order of reaction) (A) Zero order (B) First order (C) Second order (D) Third order List-II (Unit of rate constant) (I) ${\text{mol}}^{-1}\text{L}{\text{s}}^{-1}$ (II) ${\text{mol}}^{-2}{\text{L}}^2{\text{s}}^{-1}$ (III) ${\text{s}}^{-1}$ (IV) $\text{mol}{\text{L}}^{-1}{\text{s}}^{-1}$ Choose the correct answer from the options given below :

Answer: (B) (A)-(IV), (B)-(III), (C)-(I), (D)-(II). \textbf{Answer:} (B) (A)-(IV), (B)-(III), (C)-(I), (D)-(II) \textbf{Solution:} The unit of the rate constant for an $n$th order reaction is $(\text{mol}{\text{L}}^{-1}{)}^{1-n}{\text{s}}^{-1}={\text{mol}}^{1-n}{\text{L}}^{n-1}{\text{s}}^{-1}$ Zero order $(n=0)$: $\text{mol}{\text{L}}^{-1}{\text{s}}^{-1}\to$ (IV) First order $(n=1)$: ${\text{s}}^{-1}\to$ (III) Second order $(n=2)$: ${\text{mol}}^{-1}\text{L}{\text{s}}^{-1}\to$ (I) Third order $(n=3)$: ${\text{mol}}^{-2}{\text{L}}^2{\text{s}}^{-1}\to$ (II) Hence (A)-(IV), (B)-(III), (C)-(I), (D)-(II).