Density and Excess Molar Volumes of 1‑Butanol + Methanol + Electrolyte Systems in the Temperature Range 293.15–308.15 K

Methanol, unlike water, is miscible with 1-butanol in all proportions however not much work is available on binary mixtures of the two alcohols. Investigation of 1-butanol–methanol binary system (the mixture) can be interesting also for its general and industrial applications. In the present study densities over the entire composition range of the mixture have been measured from 293.15 to 308.15 K, which allowed determination of excess molar volume (V E) at four different temperatures. Structural information on the mixture has been obtained by adding sparingly soluble NaCl, KCl (borderline) and fairly soluble CdI2 (structure-breaker). Limited solubility of NaCl and KCl restricted the study only to their saturated solutions in the mixture. On the other hand using density data of CdI2 solutions of different molalities (from 4.0·10–3 to 8.0·10–2 mol·kg–1) in the mixture at the above temperatures, apparent molar (V Φ) and partial molal (V m°) volumes of CdI2 have been determined. The data also enabled determination of (α) a quantity related to the thermal expansion coefficient.