论文部分内容阅读
含醛基的物质都能发生银镜反应。醛基所连接的基团不同,其还原性的强弱也不同,还与溶液的酸碱度有很大关系。在银氨溶液中不加强碱时醛基的还原性的强弱顺序是:甲醛→葡萄糖→乙醛→甲酸。加强碱时在银镜反应中醛基的还原性强弱顺序是:甲醛→乙醛→葡萄糖→甲酸。而碱的用量一般不能过大,因为银镜的光亮度随碱量的增多而发黑。
Silver mirror reaction can occur in all aldehyde-containing materials. The aldehyde group is different in the group to which it is attached, and its reducing power is also different. It also has a great relationship with the pH of the solution. The order of the reducibility of the aldehyde groups when the base is not reinforced in the silver ammonia solution is: formaldehyde→glucose→acetaldehyde→formic acid. The order of the reducing ability of the aldehyde group in the silver mirror reaction when the base is strengthened is: formaldehyde→acetaldehyde→glucose→formic acid. The amount of alkali is generally not too large, because the brightness of the silver mirror blackens with the increase in the amount of alkali.