问题 选择题

利用右图装置制取Cu2O,乙的总反应化学方程式为:2Cu+H2O=Cu2O+H2↑。下列说法正确的是

A.乙中Cu电极的电极反应式是:

2Cu + 2OH→ Cu2O+ H2O+ 2e

B.甲中通入氢气的电极为正极

C.乙中阴离子向石墨电极移动

D.电路上通过0.5 mol电子,可制得0.5 mol Cu2O

答案

答案:A

甲装置为燃料电池装置,其中通入氢气的一极为负极,通入氧气的一极为正极;乙装置为电解池,铜片与正极相连为阳极,石墨为阴极;所以

A正确,乙中Cu电极的电极反应式为2Cu + 2OH→ Cu2O+ H2O+ 2e

B错,甲中通入氢气的电极为负极;

C错,乙中阴离子向铜电极(阳极)移动;

D错,电路上通过0.5 mol电子,可制得0.25 mol Cu2O

阅读理解

阅读理解。

     The clock struck eleven at night. The whole house was quiet. Everyone was in bed except me. Under the

strong light, I looked sadly before me at a huge pile of that troublesome stuff (东西) they call "books".

     I was going to have my examination the next day."When can I go to bed?" I asked myself. I didn't answer,

In fact I dared not.

     The clock struck twelve."Oh, dear!" I cried."Ten more books to read before I can go to bed!" We pupils

are the most unhappy creatures in the world. Dad does not agree with me on this. He did not have to work so

hard when he was a boy.

      The clock struck one. I was quite desperate (绝望的) now. I forgot all I had learned. I was too tired to go

on. I did the only thing I could. I prayed, "Oh, God, please help me pass the exam tomorrow. I do promise to

work hard afterwards, Amen." My eyes were so heavy that I could hardly open them. A few minutes later,

with my head on the desk, I fell asleep.

1. When the author was going over his lessons, all the others in the house were _____.

A. asleep

B. outside

C. working in bed

D. quietly laughing at him

2. Reviewing his lessons didn't help him because ______ .

A. it was too late at night

B. he was very tired

C. his eyes lids were so heavy that he couldn't keep them open

D. he hadn't studied hard before the examination

3. What do you suppose happened to the author the second day?

A. He went to a church to pray again

B. He got an A in the exam

C. He failed in the exam

D. He was punished by his teacher

4. The best title for the passage would be ______.

A. The Night Before the Examination

B. Working Far into the Night

C. A Slow Student

D. Going Over My Lessons

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