论文部分内容阅读
一、从制氢气废液中制取ZnSO4·7H2O或无水ZnCl2 实验用品:制氢气废液、锌粒、浓盐酸、蒸发皿、三脚架、酒精灯。操作过程:把锌粒加入废液中,放置过夜后进行过滤,将滤液放入蒸发皿中,加热蒸发。如果是硫酸锌废液,将滤液蒸发至液面开始有结晶出现时,冷却,可制得ZnSO4·7H2O。如果是氯化锌废液,在蒸发皿中蒸发结晶至糊状时,再加入少量浓盐酸,蒸发至干,可得到无水ZnCl2。
1. Prepare ZnSO4·7H2O or anhydrous ZnCl2 from the hydrogen waste liquid. Experimental supplies: Hydrogen waste liquid, zinc particles, concentrated hydrochloric acid, evaporating dish, tripod, and alcohol lamp. Operation process: The zinc particles are added to the waste liquid and filtered overnight. The filtrate is placed in an evaporating dish and heated and evaporated. If it is zinc sulphate waste liquid, the filtrate will evaporate to the liquid surface and crystals will appear. When cooling, ZnSO4·7H2O can be obtained. If it is a waste liquid of zinc chloride, it will evaporate and crystallize into a paste in an evaporating dish, then add a small amount of concentrated hydrochloric acid and evaporate to dryness to obtain anhydrous ZnCl2.