The apparent molar volumes of aqueous ammonia, ammonium chloride, aniline and anilinium chloride at 25°C and the volume changes on ionization

Abstract

The apparent molar volumes of aqueous ammonia, ammonium chloride, aniline and anilinium chloride are measured up to 2 mol l^-1 at 25°C by a combination of pyknometric and dilatometric methods. The apparent molar volume f°_V of undissociated ammonia at infinite dilution is found to be 24.85±0.02 cm³ mol^-1, and that of NH₄Cl is 35.71±0.02 cm³ mol^-1. The volume change on ionization for the standard states ΔV° is -29.07±0.04 cm³ mol^-1. For aniline the values are: f°_V(PhNH₂) 89.30, f°_V(PhNH₃Cl) 102.7₄ and ΔV° -26.49±0.05 cm³ mol^-1.