有机酸热力学性质的研究——Ⅰ.草酸、丙二酸、丁二酸、酒石酸 己二酸在盐酸溶液中的溶解热

本研究用RD—Ⅰ型热导式自动量热器测定了无水草酸、丙二酸、丁二酸、已二酸、酒石酸和二水合草酸在盐酸中的溶解热,并计算了草酸的水合热。实验结果表明,二元羧酸溶于盐酸是一个吸热过程,溶解焓为正值,且随着碳链的增长而增大,但增加的速度减慢,对于碳链相同的二元羧酸,羟基的引入,使得溶解焓减小。

STUDIES ON THERMODYNAMIC PROPERTIES OF ORGANIC ACIDS I.ENTHALPIES OF SOLUTION OF SOME DICARBOXYLIC ACIDS IN HYDROCHLORIC ACID

In present paper the molar enthaipies of solution of anhydrous oxalic acid, malonic acid, succinic acid, tartaric acid, adpic acid and dihydrated oxalic acid in 0. 1 N hydrochloric acid at ordinary presssure and 298. 15K were measured with a conduction type automatic calori- meter, the enthalpies of hydration of the oxalic acid was also estimated. The experiments reported here have shown that the process dissolving dicarboxylic acids in hydrochloric acid is an endothermic one, that is, the enthalpies of solution are all posi- tive. They increase as the carbon chain is lengthened but decrease with introducing hydroxyl groups to the chain.