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问题 填空题

（13分）现有某XY3气体m g，它的摩尔质量为M g·mol-1。若阿伏加德罗常数用NA表示，则：

（1）该气体的物质的量为                    

（2）该气体所含原子总数为                    个

（3）该气体在标准状况下的体积为                

（4）该气体溶于1L水中（不考虑反应），其溶液中溶质的质量分数为          

（5）该气体溶于水后形成VL溶液，其溶液的物质的量浓度为                   ；

将该溶液加水稀释至原体积的2倍后，再取出50mL稀释后的溶液，则取出溶液的物质的量浓度为                       

（6）标准状况下，相同体积的另一种气体CH4含有氢原子的物质的量为            

答案

（13分）（1）m/M  mol  (数值和单位都正确得1分)（2）4mNA/M   （2分）

（3）22.4m/M  L(2分，数值和单位各得1分)

（4）m/(m+1000)   (2分，也可以带100%符号)

（5）m/MV mol·L -1 (2分，数值和单位各得1分)  

 m/2MV mol·L -1(2分，数值和单位各得1分)

(6) 4m/M  mol   (2分，数值和单位各得1分)

单项选择题

Generally speaking, a British is widely regarded as a quiet, shy and conservative person who is (1) only among those with whom he is acquainted. When a stranger is at present, he often seems nervous, (2) embarrassed. You have to take a commuter train any morning or evening to (3) the truth of this. Serious-looking businessmen and women sit reading their newspapers or dozing in a corner; hardly anybody talks, since to do so would be considered quite offensive. (4) , there is an unwritten but clearly understood code of behavior which, (5) broken, makes the offender immediately the object of (6) .

It has been known as a fact that a British has a (7) for the discussion of their weather and that, if given a chance, he will talk about it (8) . Some people argue that it is because the British weather seldom (9) forecast and hence becomes a source of interest and (10) to everyone. This may be so. (11) a British cannot have much (12) in the weathermen, who, after promising fine, sunny weather for the following day, are often proved wrong (13) a cloud over the Atlantic brings rainy weather to all districts! The man in the street seems to be as accurate — or as inaccurate — as the weathermen in his (14) .

Foreigners may be surprised at the number of references (15) weather that the British make to each other in the course of a single day. Very often conversational greetings are (16) by comments on the weather. "Nice day, isn’t it" "Beautiful!" may well be heard instead of "Good morning, how are you" (17) the foreigner may consider this exaggerated and comic, it is worthwhile pointing out that it could be used to his advantage. (18) he wants to start a conversation with a British but is (19) to know where to begin, he could do well to mention the state of the weather. It is a safe subject which will (20) an answer from even the most reserved of the British.

17（）

A. Since

B. Although

C. However

D. Only if
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判断题

蒸汽供给恢复后应立即启动燃料油泵。（）
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