JEE Main 2023 — Chemical Kinetics Question with Solution

A. ${\mathrm{C}}_0\stackrel{\mathrm{t}=\frac{{\mathrm{C}}_0}{2\mathrm{k}}}{⟶}\frac{{\mathrm{C}}_0}{2}\stackrel{\mathrm{t}=\frac{{\mathrm{C}}_0}{4\mathrm{k}}}{⟶}\frac{{\mathrm{C}}_0}{4}\stackrel{\mathrm{t}=\frac{{\mathrm{C}}_0}{8\mathrm{k}}}{⟶}\frac{{\mathrm{C}}_0}{8}$

Successive half lives of zero order reactions decreases with time

Note: successive half lives of first order reactions remains same

B. For zero order reactions, the rate of reaction is independent on the concentration of reactants.

C. In some reaction molecularity (theoretical value) may be equal to the order of a reaction (experimental value). The order  of a reaction may be fractional, zero, positive or negative. Molecularity can never be fractional.

(D) Unit of $\mathrm{k} = \frac{\mathrm{Units} \mathrm{of} \mathrm{rate}}{{\left[\mathrm{units} \mathrm{of} \mathrm{concentration}\right]}^{\mathrm{order}}}$ 

Zero order $={\mathrm{mollit}}^{-1}{\sec }^{-1}$

Second order $={\mathrm{mol}}^{-1}{\mathrm{lit}}^{-1}$