摘要
根据热力学平衡原理和设计的可逆电池反应,由 E^0(Hg^(2+)+S/HgS)数据,计算了 E^0(HgCl_4^(2+)+S/HgS+4Cl^-)数值,将其与 HNO_3的标准电极电位比较,定量地揭示了 HgS 溶于王水的原因在于该溶液中高浓度 Cl^-离子降低了 HgS 中硫的还原电位,从而提高了 HgS 的还原性所致,并非王水的氧化性比 HNO_3的更强。根据这个机理,作者进一步对有关电极反应的电极电位进行了计算和分析,预测并经实验验证了多种可以溶解 HgS 的普通化学试剂。
Based on the principle of thermodynamic equilibrium and the designed reversible cell reac- tion,the value of E^0(HgCl_4^(2-) +S/HgS+4Cl^-) was obtained from the value of E^0(Hg^(2+)+S/HgS). Comparing it with the standard electrode potential of nitric acid,the reason of dissolution of HgS in aqua regia was quantitatively revealed,and this is that the high concentration of chloride ions reduces the reduction potential of sulfur in HgS,thus raising the reducing power of HgS rather than that the oxidizing power of aqua regia is stronger than that of nitric acid.After calculating the standard elec- trode potentials of some electrode reactions concerned,many common chemical reagents capable of dissolving mercuric sulfide were predicted and experimentally verified.
关键词
硫化汞
电极
电位
溶解
电解质溶液
mercuric sulfide
aqua regia
oxidant
ligand
standard electrode potential
