问题 问答题

将16g硫在给定质量的氧气中燃烧,有如下数据:

组别123456
给定的O2质量/g101516202432
生成的SO2质量/g203032324832
(1)观察、分析表中数据,有明显误差的是哪一组?______.

(2)观察分析表中数据,可以得出的结论是

______

______.

答案

由题意可知16g硫的质量是确定的,观察、分析表中数据,通过对比1、2组的数据可得出:当给定氧气的质量增加时,生成的二氧化硫的质量也在增加,说明第一组中的10克氧气完全参加了反应,由质量守恒定律可知,参加的反应硫的质量也是10克,硫剩余6克,由此又可以推出,硫与氧气发生化学反应的质量比为1:1.由硫与氧气发生化学反应的质量比为1:1,还可以推出当16g硫在给定大于16克的氧气中燃烧时时,氧气有剩余,最多可生成32克的二氧化硫.观察、分析表中数据,有明显误差的是第5组.

故答为:(1)5.

(2)①硫与氧气发生化学反应时的质量比为1:1,

②16g硫最多可生成32g二氧化硫.

单项选择题
阅读理解

阅读理解。

     The Japanese love to give gifts. This habit is not practiced only on special occasions, but it's

widely accepted as social duty and responsibility. Because gift-giving is such an important social

aspect of Japanese life. It's important to be aware of some key factors.

     Devalue the gifts you give. The important thing is to act and seem modest. You don't

want the receiver to think that you are arrogant or proud. Denigrate(贬低) your gift as much as

possible. It doesn't matter if the label on the box bears the symbol for a famous brand. The

Japanese value the appearance of a modest gift-giver who tries to stay away from praise.

     Praise the gift you receive. Although praising may seem obvious, overpraising the gift is

the key. It's also important to praise the fine taste of the gift-giver in making that particular choice

for you. And don't forget to give a thousand and one thanks.

     Unless you are urged to do so. And when you do, you must take the utmost care in

unwrapping it. Don't look eager, and be careful that you don't tear the paper or cut the ribbon.

After observing, praising, and thanking, be sure to rewrap the gift as if it had never been opened.

Try to appear as if you take great pride in the value of the gift.

     Choose gifts with practical value. In general, don't buy things such as ornaments, vases,

and kitchenware; it's already assumed that everyone has these things. To do so may suggest that

you don't approve of the other person's taste. Also, most Japanese houses are very small and

don't have extra space for useless junk.

1. What is the best title for the passage? (no more than l0 words)

                                                                                  

2. Fill in the blank in the fourth paragraph with proper words. (no more than 6 words)

                                                                                  

3. List three kinds of things you'd better not buy for a Japanese friend.

   ①                         

   ②                        

   ③                        

4. Translate the underlined sentence in the first paragraph into Chinese.

                                                                                   

                                                                                  

5. What do the Japanese usually do when they receive a gift? (no more than l0 words)