问题 问答题

小刚设计实验探究铁、铜、银三种金属的活动性顺产并分析相关问题.请填空:

(1)他设计的四种实验方案,所需试剂如下:

①铜、银、硫酸亚铁溶液               ②铁、银、硫酸铜溶液

③银、硫酸亚铁溶液、硫酸铜溶液       ④铜、硫酸亚铁溶液,硝酸银溶液

上述方案中,正确的是______(填写序号).

(2)某化工厂生产过程中的残液含有硝酸银和硝酸铜两种物质.小刚取少量该残夜,分别盛在A、B两支试管中,再分别加入不同质量的铁粉,充分反应后过滤,分别取滤渣或滤液进行下表所示实验:

    实验操作实验现象    分析与结论
将A试管滤出的滤渣洗涤后加入到稀盐酸中有气泡产生从A试管得到的滤液中的溶质是______
向B试管得到的滤液中滴加少量稀盐酸有白色沉淀生成B试管滤出的滤渣的成分是______

答案

(1)根据金属活动性顺序K、Ca、Na、Mg、Al、Zn、Fe、Sn、Pb、(H)、Cu、Hg、Ag、Pt、Au,则可知铁、铜、银三种金属的活动性,则可推测实验方案的设计是否合理的为:铁、银、硫酸铜溶液;铜、硫酸亚铁溶液,硝酸银溶液,故选②、④.

(2)某化工厂生产过程中的残液含有硝酸银和硝酸铜两种物质.小刚取少量该残夜,分别盛在A、B两支试管中,再分别加入不同质量的铁粉,充分反应后过滤,分别取滤渣或滤液进行下表所示实验:

①将A试管滤出的滤渣洗涤后加入到稀盐酸中,有气泡产生,说明铁粉过量,硝酸银和硝酸铜反应完全,则可知从A试管得到的滤液中的溶质;

②向B试管得到的滤液中滴加少量稀盐酸,有白色沉淀生成,说明为稀盐酸与硝酸银反应,则说明硝酸银过量,则可知B试管滤出的滤渣的成分.故表格为:

    实验操作实验现象    分析与结论
将A试管滤出的滤渣洗涤后加入到稀盐酸中有气泡产生从A试管得到的滤液中的溶质是Fe(NO32
向B试管得到的滤液中滴加少量稀盐酸有白色沉淀生成B试管滤出的滤渣的成分是Ag
故答为:(1)②④;(2)Fe(NO32;Ag

阅读理解

阅读理解。

  A large number of people in the world eat fast food. Whenever you go into a fast food restaurant,

you can see lots of people enjoying their meals there. How do you know in which country people like fast

food best?   

  The English, people are the world's biggest fans of fast food, while the French(法国人)are the least

interested in quick meals according to a survey done last year.   

  The survey of thirteen countries shows 45% of the English people say they can't give up fast food

because it's delicious. And 44% of Americans and 37% of Canadians say the same.    

  The French, proud of their delicious and high-class cuisine, don't like fast food. 81% of them think it

is' unhealthy, followed by 75% of the Japanese.  

  How about the Chinese? How often do you have hamburgers or fried chicken? It doesn't matter

whether you like Western fast food or Chinese food. The most important thing is to keep a balanced diet.

1. From the survey we know _______fast food best. 

A. the Chinese    

B. the French    

C. the Japanese    

D. the English

2. The survey shows _______ of Americans like fast food.

A. 37%

B. 44%    

C. 75%

D. 81%

3. According to the survey some people can't give up fast food because _______.    

A. it's cheap    

B. it's safe    

C. it’s delicious    

D. it's healthy

4. The underlined word“cuisine”in the passage means _______.    

A. food        

B. house    

C. water      

D. country

5. The survey is about _______.

A. Western countries    

B. fast food    

C. restaurants in the world    

D. Chinese food

名词解释