MHTCET 15 May 2024 Shift 2 Paper

Concept:For a weak electrolyte, the degree of dissociation $\alpha$ is the ratio of molar conductivity at a given concentration $\Lambda_c$ to the molar conductivity at infinite dilution $\Lambda_0$.Percentage dissociation is obtained by multiplying $\alpha$ by $100$.Explanation:The formula for degree of dissociation is:$$\alpha = \frac{\Lambda_c}{\Lambda_0}$$Here, $\Lambda_c = 3.3\ \Omega^{-1}\ \mathrm{cm}^2\ \mathrm{mol}^{-1}$ and $\Lambda_0 = 132\ \Omega^{-1}\ \mathrm{cm}^2\ \mathrm{mol}^{-1}$.Substitute the given values into the formula:$$\alpha = \frac{3.3}{132}$$Simplify the fraction:$$\alpha = \frac{1}{40} = 0.025$$Convert the degree of dissociation to percentage:$$\text{Percentage dissociation} = \alpha \times 100 = 0.025 \times 100 = 2.5\%$$Thus, the percentage dissociation of the weak electrolyte is $2.5\%$.Answer:Option C: $2.5\%$