问题 选择题

三聚氰酸[C3N3(OH)3]可用于消除汽车尾气中的NO2。其反应原理为:

① C3N3(OH)33HNCO

② 8HNCO+6NO27N2+8CO2+4H2O

(两个方程式中所有碳元素的化合价均为+4)

下列说法正确的是

A.反应①、②均是氧化还原反应

B.反应②中N2既是氧化产物、又是还原产物

C.反应②中,每转移1mol电子,NO2被氧化0.25 mol

D.反应②中氧化剂、还原剂的物质的量之比为4∶3

答案

答案:B

正确答案:B

A.不正确,反应②是氧化还原反应,①是非氧化还原反应;

B.正确,反应②中N 从-3价和+4价均变成0价, N2既是氧化产物、又是还原产物

C.不正确,反应②中,每转移1mol电子,NO2中氮降4价,NO2被还原0.25 mol

D.不正确,反应②中氧化剂、还原剂的物质的量之比为6:8=3∶4

多项选择题
阅读理解

阅读表达。

     Speaking of what sort of smartness is most desirable in human conduct, a friend of mine has this to say:

Real stnartness must be something that can be practised repeatedly and infinitely. Then, he goes on to relate

this event: In one European country there resided some Lebanese. Upon learning that ambulance rides there

are provided free to patients in emergency cases, they rented an apartment near a hospital. Each time they

wanted to go home, they just pretended to be sick, calling for an ambulance. On arrival at the hospital, they

said now that they felt much better and had no need of any treatment. The next moment saw them leaving,

safe and sound, to their apartment.

     Their "being-clever" affords them only short-lived pleasure and joy; it could not he practised repeatedly,

still less infinitely. Such smartness is based on "too clever to be wise". Once seen through, they will lose the

benefits they profited by playing dirty tricks. They will suffer the impairment of their own image and reputation

as well as that of those who are tied with them by blood or by common interests.

     When a person has done something to the discredit of one's own image and reputation, it will surely involve

others related to him in one way or another. Among those inflicted most hy what folly (愚蠢) he may have

done are those who, to him, have been close in relations and dear in sentiment.

     Additionally, whether one's act is wise or unwise, rather the summit of wisdom, depends on the result of

the act; if _____, then the more often he does it, the better will he be believed. While repeating that act, he is

not only earning himself an admirable image but also contributing to the fine impression and reputation of his

relatives, his friends, his hometown and his motherland.

1. What does the passage mainly discuss? (please answer within 10 words.)

    ______________________________________________________________________________________

2. Please fill in the blank in the last paragraph with proper words or phrases to complete the sentence. (please

    answer within 10 words.) 

    ______________________________________________________________________________________

3. Which sentence in the passage can be replaced by the following one? People that have ruined their own

    images not only hurt themselves but will involve their relatives or friends. 

    ______________________________________________________________________________________

4. How would the telephone operators react to a Lebanese voice calling for an ambulance from then on? (please

   answer within 10 words.) 

    ______________________________________________________________________________________

5. Translate the underlined sentence in the last paragraph into Chinese.

    ______________________________________________________________________________________