题目内容
【题目】充分燃烧某糖,消耗的氧气、生成的CO2和H2O的物质的量都相等,它的相对分子质量是它实验式的5倍,0.1 mol该糖能与24 g乙酸发生酯化反应,且该糖能与银氨溶液发生银镜反应。求:
(1)该糖的实验式。
(2)该糖的相对分子质量、分子式。
(3)若该糖是直链分子,同一个碳原子上连有2个羟基不稳定,推导出它的结构简式。
【答案】(1)CH2O
(2)150 C5H10O5
(3)CH2OHCHOHCHOHCHOHCHO
【解析】据“充分燃烧某糖,消耗的氧气、生成的CO2和H2O的物质的量都相等”可得出实验式为CH2O,再据“它的相对分子质量是它实验式的5倍”可确定其相对分子质量和分子式分别为150和C5H10O5;然后确定它的分子结构:“0.1 mol该糖能与24 g乙酸发生酯化反应,且该糖能与银氨溶液发生银镜反应”,首先说明该糖分子中同时有羟基和醛基,根据“0.1 mol该糖能与24 g乙酸发生酯化反应”,可计算出羟基数目为4个。
【题目】
用方框中所给短语的适当形式填空。
have (got) to had better would rather cannot help but be supposed to used to be about to be able to |
【1】 He escape from the burning house with the help of the firefighters.
【2】You take a raincoat with you, It's going to rain this afternoon
【3】 I jump into the river when the guide suddenly stopped me.
【4】 I go now. After all, I promised my parents to go home early.
【5】 Jack go to work on foot than take a bus, which is good for health.
【6】 He be a naughty boy, but now he studies very hard.
【7】 I laugh as the joke was so funny.
【8】 All of us protect the environment to live in harmony with nature.