论文部分内容阅读
甲酸,可以将它看作羟酸,又可将它看作带一个羟基的甲醛,因此它同醛类一样,可以和银氨溶液起银镜反应:HCOOH+2Ag(NH_3)_2OH=2Ag↓+CO_2+2H_2O+4NH_3但人们通常用甲酸代替醛类做银镜反应时,还原出来的银常常不是银镜的样子,而是黑色的沉淀。现介绍如下的实验方法,能得到较为理想的银镜。1、试管处理取一支硬质试管加浓硝酸5毫升,置于沸水浴中加热1-2分钟,倾去硝酸,用自来水冲洗后,加入10％氢氧化钠溶液5毫升,同样于沸水浴中加热1-2分钟,倾去碱液,分别用自
Formic acid, it can be seen as a hydroxy acid, it can be seen as a formaldehyde with a hydroxyl group, so it is the same as aldehydes, silver mirror reaction with silver ammonia solution: HCOOH + 2 Ag (NH_3) _2OH = 2Ag ↓ + CO_2+2H_2O+4NH_3 But when people usually use formic acid instead of aldehydes for the silver mirror reaction, the silver that is recovered is often not a silver mirror but a black precipitate. Now introduce the following experimental methods, can get a better silver mirror. 1, tube processing Take a hard test tube and concentrated nitric acid 5 ml, placed in boiling water bath heating 1-2 minutes, decanted nitric acid, rinse with tap water, add 10% sodium hydroxide solution 5 ml, the same in the boiling water bath Heat in 1-2 minutes, pour lye, use separately