问题 问答题

下列关于agH2和bgHe的说法正确的是(  )

A.同温同压下,H2和He的体积比是a:2b

B.同温同压下,若a=b,则H2与He的物质的量之比是1:1

C.体积相同时,He的质量一定大于H2的质量

D.同温同压下,若二者的物质的量相等,其体积也相等

答案

A、agH2的物质的量为

ag
2g/mol
=0.5amol,bgHe的物质的量为
bg
4g/mol
=0.25mol,同温同压下,体积之比等于物质的量之比,所以H2和He的体积比为0.5amol:0.25bmol=2a:b,故A错误;

B、由A可知H2和He的物质的量之比为0.5amol:0.25bmol=2a:b,如a=b,则2a:b=2:1,故B错误;

C、氦的摩尔质量比氢气大,体积相同时,若温度、压强相同,则He的质量一定大于H2的质量,但体积相同时,气体的物质的量与压强、温度有关,无法确定气体的物质的量,故无法判断其质量关系,故C错误;

D、同温同压下,气体摩尔体积为定值,二者的物质的量相等,其体积也相等,故D正确.

故选:D.

阅读理解

Andy was still traveling in Spain when he realized he had to confirm(确认) his    home with the airline company. He was visiting Spain in order to improve his Spanish. When he was speaking to people face to face, he had no difficulty understanding what they said. However, when he was speaking on the phone, he still had a problem. Andy called the airline. And the clerk confirmed that his plane was leaving at nine o’clock three days from that day. She also told Andy to be at the airport a little earlier in order to check in his luggage and get a seat.

Since he was leaving in three days, Andy didn’t lose any time. He visited as many places as he could. He thought that it would probably be a while before he had enough money again. He wished he could come back and spend a year in Spain.

Too quickly, the final day arrived. Andy left early for the airport before take-off. He hated to rush. When he went to the clerk to show his ticket, the clerk looked at the ticket in surprise , “Why, sir, but your flight was at nine o’clock in the morning, and now it is eight in the evening.”“But I confirmed my flight,”insisted Andy.“Will I have to pay for another ticket?”

“No, Sir. However, the next flight out will be three days from now.”

Andy’s     of shock turned to smile as he realized that now he could go on with his vacation.

任务一:请根据短文内容,分别写出①、②处所缺单词。(每空限填一词)

小题1:①______________   ②______________

任务二:根据短文内容补全句子。(每空限填一词)

小题2:(A) He visited as many places as _____________.

(B)From the passage we know Andy could ____________ his holiday.

任务三:请把上文中画线的句子翻译成汉语。

小题3:_________________________________________________________

任务四:请根据短文内容回答下列问题。

小题4:Why did the clerk tell Andy to be at the airport a little earlier?

________________________________________________________

小题5:How long was Andy late for the plane that day?

_________________________________________________________

选择题