Question

Calculate the molar conductivity at infinite dilution (ꓥ°) for potassium ethanoate (CH3COOK) from the following ꓥ° data using Kohlrausch’s Law:

HBr
385 S cm2 mol-1
KBr
106 S cm2 mol-1
CH3COOH
391 S cm2 mol-1

Answer 1

Solution.

$CH3COOH + KBr = CH3COOK + HBr$

$\lambda^0 (CH3COOK) = \lambda^0 (CH3COOH) + \lambda^0 (KBr) - \lambda^0 (HBr)$

$\lambda^0 (CH3COOK) = 391 + 106 - 385 = 112 \ S \ cm2 \ mol-1$

Answer:

$\lambda^0 (CH3COOK) = 112 \ S \ cm2 \ mol-1$