Apparent molal volumes of sodium salts of some aliphatic carboxylic acids in water at 298.15 K

Abstract

The apparent molal volumes, of three series of homologous organic sodium salts of the H(CH2) n COONa [n = 1–8], (CH2) n (COONa)2 [n = 0–6], Cl(CH2) n COONa [n = 1–4] types and sodium salts of some unsaturated carboxylic acids (ethylenecarboxylic acid, 3-butenoic acid, 4-pentenoic acid, trans-2-pentenoic acid, trans-2-hexenoic acid and 2-octenoic acid) in dilute aqueous solution have been determined by density measurements at T = 298.15 K. The densities were measured using a vibrating-tube densimeter (DMA 5000, Anton Paar, Austria) at T = 298.15 K. These results were used to calculate the apparent molal volumes of each solute over the concentration range 0.0050 ≤ m mol kg−1 ≤ 0.3000. The concentration dependence of apparent molal volumes of all studied electrolytes can be fitted to the Redlich–Meyer equation. Also, the values of limiting partial molal volume were calculated. The variations of both with aliphatic chain length of analysed salts of carboxylic acids were determined.