The molar conductivities at infinite dilution for sodium acetate, hydrochloric acid and sodium chloride are 91.0, 425.9 and 126.4 S cm² mol^-1 respectively at 298 K. Calculate the molar conductivity of acetic acid at infinite dilution.

390.5 S cm² mol^-1

Molar conductivity at infinite dilution for acetic acid can be calculated as:
∧°_(CH3COOH) = λ°_H⁺ + ∧°_CH3COO^–
= λ_CH3COO^– + λ°_Na⁺ + λ°_H⁺ + λ°_Cl^– – λ°_Na⁺ – λ°_Cl^–
∧°_(CH3COOH) = ∧°_(CH3COONa) + ∧°_(HCl) – ∧°_(NaCl)
∧°_(CH3COONa) = 91.0 S cm² mol^-1
∧°_(HCl) = 425.9 S cm² mol^-1
∧°_(NaCl) = 126.4 S cm² mol^-1
∴ ∧°_(CH3COOH) = 91.0 + 425.9 – 126.4 = 390.5 S cm² mol^-1.