问题 填空题

(13分)(1)将锌、铜用导线连接后浸入2mol/L的稀硫酸中,正极电极反应式为_________________,发生       反应(填氧化或还原);电子从     经外电路到     (填锌或铜),溶液中H+       移动(填正极或负极)。

(2)根据反应2Fe3+ + Cu = 2Fe2++Cu2+ 设计原电池,所需负极材料为       ,溶液中Fe3+      (填“负极”或“正极”)迁移,负极反应式为              ;正极反应式为                   

答案

(1)2H++2e-=H2↑   还原   锌   铜   正极

(2)Cu、正、 Cu-2e-=Cu2+    2Fe3+ +2e- = 2Fe2+

题目分析:(1)将锌、铜用导线连接后浸入2mol/L的稀硫酸中形成原电池,该原电池中锌是负极,发生氧化反应,铜是正极,溶液中的氢离子得电子生成氢气,发生还原反应,电极反应式为2H++2e-=H2↑;外电路上,电子从负极沿导线到正极,即电子是从锌经外电路到铜;溶液中H+ 向正极移动。(2)根据反应2Fe3+ + Cu = 2Fe2++Cu2+ 设计原电池,铜的化合价由0价升高为+2价,发生氧化反应,作原电池的负极,电极反应式为Cu-2e-=Cu2+;电解质溶液中阳离子Fe3+向正极迁移,在正极上发生还原反应,电极反应式为2Fe3+ +2e- = 2Fe2+

阅读理解

阅读理解。

     In Japan, you say "itadakimasu"("I am going to start")before eating, and "gochisosam(deshita)"

("Thank you for the meal")after finishing the meal.

◆Eating rules

     Blowing your nose in public, and especially at the table, is considered bad manners.It is considered

good manners to eat up all the things in your plate.Unlike in some other parts of East Asia, it is

considered bad manner to burp(打嗝).After eating, try to move all your dishes back to the same

position they were at the start of the meal.

◆Drinking rules

     When drinking alcohol(酒), it is a good manner to serve each other, instead of serving yourself.

Check your friends' cups from time to time and refill(重新注满)their drinks if their cups are getting

empty.If someone wants to serve you more alcohol, you should quickly empty your glass and hold

it towards that person.

     While it is considered bad manners to become drunk in some formal restaurants, the same is not

true for other small restaurants, as long as you do not trouble other guests.

     Do not start drinking until everybody at the table is served and the glasses are raised for a drinking

salute(口号), which usually is "kampai".

1.In Japan, you say "itadakimasu" ______.  

A.before eating

B.while eating

C.after eating

D.before drinking

2.All these are good manners in Japan except ______.

A.eat up all the things in your plate

B.after eating, move all your dishes back

C.serve alcohol to each other

D.blow your nose in public

3.From the second paragraph we may know that ______.  

A.in Japan you may burp after eating 

B.in some East Asian countries you may burp after eating

C.in some West Asian countries you may burp after eating

D.in the western countries you may burp after eating

4.If someone wants to serve you more alcohol in Japan, you should______.    

A.serve them quickly

B.refuse it politely

C.say "That's enough"

D.empty your glass and hold it

5.Which of the following is the right drinking rule?  

A.When drinking alcohol, it is a good manner to serve yourself.

B.Check your friends' cups from time to time and refill them if they are empty.

C.It is considered bad manners to become drunk in all the restaurants.

D.Start drinking if only one person is not served.

单项选择题