The apparent molal volumes, ΦV's, of dilute (0.002-1m) aqueous solutions of NaF, Na2SO4, KCl, K2SO4, MgCl2, and MgSO4 are determined at 0° and 50°C from precision density measurements made with a magnetic float densitometer. The infinite dilution apparent molal volumes, ΦV°'s, are determined by using the Redlich equation, ΦV = ΦV° + SVc1/2 + bVc, where SV is the Debye-Hückel limiting law slope, and by is a deviation constant. At 0°C the deviations are positive for all the salts except MgCl2. The temperature dependence of the by for all the salts is similar to other commnn electrolytes (∂bV/∂T is negative). The effect of temperature on the ΦV°'s of all the electrolytes is similar in that ∂2ΦV°/∂T2 is negative. The ion-ion and ion-water interactions responsible for the observed behavior of the ΦV's are briefly discussed.
ASJC Scopus subject areas
- Chemical Engineering(all)