390.7.
517.2
217.5
552.7
Using the given data, Λ∞HOAc = Λ∞NaOAc + Λ∞HCl - Λ∞NaCl = 91.0 + 426.2 - 126.5 cm²mol⁻¹ = 390.7 S cm²mol⁻¹