问题 填空题

通过粮食发酵可获得某含氧有机化合物X,其相对分子质量为46,其中碳的质量分数为52.2%,氢的质量分数为13.0%。

(1)X的分子式是_______ ;

(2)X与金属钠反应放出氢气,反应的化学方程式是_____________________________________(有机物用结构简式表达);

(3)X与空气中的氧气在铜或银催化下反应生成Y,Y的结构简式是______________;

(4)X与高锰酸钾酸性溶液反应可生成Z。在加热和浓硫酸作用下,X与Z反应可生成一种有香味的物质W,若184 g X和120 g Z反应能生成106 g W,计算该反应的产率。(要求写出计算过程)

答案

(1)C2H6O

(2)2C2H5OH+2Na→2C2H5ONa+H2

(3)CH3CHO

(4)设乙酸乙酯的理论产量为x。

选择题
阅读理解

We Americans are wasteful people, not used to saving. Early settlers, our forefathers set us an example of wasting everything, for they thought nature’s resources were so plentiful that none of them ever imagined that natural materials would be used up in time. Within a few years of the first Virginia settlement, for example, pioneers burned down their houses when they were ready to move west. They burned down their houses with only one aim to get the nails(钉子)for future use. No one ever gave a thought to the priceless hardwoods that went up in smoke. As a people we destroy many valuable things that other people save. I noticed this when I was living in Britain. I received a letter from one England’s largest banks. It was enclosed in a used envelope(信封)that had been readdressed to me. Such a practice would be unthinkable in the United States. American banks, even the smallest, always use expensive stationery(信笺)with the names of all twenty - eight vice – presidents lists on side of the page.

小题1:According to the passage, we know the writer is ________ .

A.a Chinese

B.a Japanese

C.an Englishman

D.an American小题2:The writer thought their forefathers ________ .

A.set a good example

B.wasted many natural resources

C.knew natural resources would be used up in time

D.made the best use of natural materials小题3: Which of the following statements is wrong?

A.The writer lives in Britain now.

B.American banks use expensive stationery.

C.Americans are not used to saving.

D.The writer’s forefathers burned down their houses in order to get the nails.小题4:The purpose of the passage is to ­­­­­­­­­­­­­­­­________ .

A.wish Americans not to waste

B.tell us the English are a good people

C.warn Americans against saving

D.encourage people to work hard.