问题 计算题

大蒜是人们生活中常见的食品,同时又有药用的价值。大蒜中大蒜新素的化学式为C6H10S2,请回答:

⑴ 大蒜新素是由         种元素组成,其分子中碳、硫的原子个数比为           ,大蒜新素中碳元素、氢元素与硫元素的质量比是            

⑵ 大蒜新素的相对分子质量是           ,该物质中硫元素的质量分数是          

答案

⑴ 3 ; 3﹕1; 36﹕5 。(每空1分)

⑵ 146 , 43.8% 。(每空2分)

题目分析:1、由大蒜新素的化学式C6H10S2可知,大蒜新素是由3种元素组成,其分子中碳、硫的原子个数比为3:1,大蒜新素中碳元素、氢元素与硫元素的质量比是12×6:1×10=36:5;

2、大蒜新素的相对分子质量=12×6+1×10+32×2=146;其中硫元素的质量分数=="43.8%" 。

点评:相对分子质量就等于各原子相对原子质量的总和;元素质量分数=

阅读理解

阅读理解。

     Tradition ways that at the begining of the sixth century one of the tribes (部落) in Ireland was called Celt.

The chief (酋长) of Celt had a beautiful daughter, named Ellis, who was from childhood, fond of having honey.

When she grew up, lots of knights (骑士) and princes from neighboring countries came to propose marriage

to her. Ellis fell in love with a young master of a southem tribe who was among the proposers. They were soon

in love with each other. At last they decided to get married. On the wedding day Ellis entertained (款待) the

honored guests with honey wine made from the honey which had been presented by the young master. After

drinking the wine the guests sang high praise for it. They said the wine was as sweet as love. But there was too

much wine for them to drink up. The bride (新娘) and bridegroom (新郎) continued drinking it next day. They

were intoxicated (沉醉) with the sweet honey wine. It took the young couple a whole month to drink it up.

     From then on it was very popular among the local people to drink honey wine within the first month after

the man and woman's marriage. They thought that it stood for the sweetness and happiness of a newly-married

couple. Later on it spread far and wide. People named the first month after marriage honeymoon (蜜月).

1. In Ireland there was a tribe named Celt _____. [ ]

A. thousands of years ago

B. after the sixth century

C. before the twenties of the 6th century

D. about fourteen centuries ago

2. Among the proposers Ellis fell in love with a young master _____. [ ]

A. of Holland

B. from a southem tribe

C. came from France

D. of her own tribe

2. Among the proposers Ellis fell in love with a young master _____. [ ]

A. of Holland

B. from a southem tribe

C. came from France

D. of her own tribe

4. How long did it take the bride and bridegroom to drink up the left over honey wine? [ ]

A. Over forty days.

B. Around a month.

C. A month less three days.

D. A full month.

5. Which title could be the best for the passage? [ ]

A. The Origin of Honeymoon.

B. How did the tribe of Celt Come Into Being.

C. Something about the Bride and the Bridegroom.

D. What Happened to a Tribe.

填空题