If the equivalent conductance of 1 M benzoic acid is 12.8 ohm-1 cm² eq-1 and if the conductance of benzoate ion and H+ ion are 42 and 288.42 ohm-1 cm² eq-1 respectively, what is its degree of dissociation?

39% 3.9% 0.35% 0.039%

3.9%

\(\Lambda _{C_6H_5COOH} = \Lambda _{C_6H_5COO^-} + \Lambda _{H^+}\) \(\Lambda _{C_6H_5COOH}\)= 42 + 288.42 = 330.42 ohm-1 cm² eq-1  α = \(\frac{12.8}{330.42}\) x 100 = 3.87 ≈ 3.9%