Question
Λ°m for NaCl, HCl and CH3COONa are 126.4, 425.9 and 91.0 s cm2 mol–1respectively. Calculate Λ° for HAC.
Solution
Λ° (HAC) = λ°(H+) + λ°(AC–)
= λ° (H+) + λ°(Cl–) + λ° (AC–) + λ° (Na+) – λ°(Cl–) – λ°(Na+)
= Λ° (HCl) + Λ° (NaAc) – Λ° (NaCl)
= (425.9 + 91.0 – 126.4) s cm2 mol–1 = 390.5 s cm2 mol–1