Volumetric properties of some aliphatic monoand dicarboxylic acids in water at 298.15 K

摘要

The apparent molar volumes, Vφ, of two series of homologous aliphatic carboxylic acids, H(CH_2)_nCOOH [n = 0-5] and (CH_2)_n(COOH)_2 [n = 0-5], were determined in dilute aqueous solutions by density measurements at T = 298.15 K. 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 molar volumes of each solute over the concentration range 0.0050 ≤ m/(mol·kg -1) ≤ 0.3000. Values of the apparent molar volumes of undissociated acids Vφ(u)0 were also calculated. The variation of Vφ(u)0 was determined as a function of the aliphatic chain length of the studied carboxylic acids.