The odd-even behaviour of dicarboxylic acids solubility in the atmospheric aerosols

The solubility and the enthalpy of dicarboxylic acids have been determined in water at intervals between 278.5 and 543.5 K. At 298.15 K, the values derived were: ?sol H m (m?=?1.33 mol kg-1)?=?29.80 kJ mol-1for oxalic acid; ?sol H m (m?=?16.03 mol kg-1)?=?12.82 kJ mol-1 for malonic acid; ?sol H m (m?=?0.75 mol kg-1)?=?28.20 kJ mol-1 for succinic acid; ?sol H m (m?=?8.77 mol kg-1)?=?48.01 kJ mol-1 and ?sol H m (m?=?0.17 mol kg-1)?=?40.30 kJ mol-1 for glutaric and adipic acid respectively. The solubility value exhibits a prominent odd–even effect with respect to terms with even number of carbon atoms with the odd carbon numbers showing much higher solubility. Observations made in the atmospheres suggest that this odd–even effect may have implications for the relative abundance of these acids in aerosols.