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问题 问答题

在标准状况下，将224LHCl气体溶于635g水中，所得盐酸的密度为1.20g/cm3，试计算：

（1）取出上述溶液10mL，稀释至60mL，其物质的量浓度为多少？______

（2）用（1）所配制的稀盐酸50mL恰好与NaOH和Na2CO3混合溶液100mL完全反应，则反应后混合溶液中Na+的物质的量是多少？______．

答案

（1）224LHCl的物质的量为

224L
22.4L/mol
=10mol，HCl的质量为10mol×36.5g/mol=365g，

635mL水的质量为635mL×1g/mL=635g，故溶液的质量为：635g+365g=1000g，

故所得盐酸的体积=

1000g
1200g/L
=
5
6
L，所得盐酸的物质的量浓度为：c=
10mol
5
6
L
=12mol/L，

取出上述溶液10mL，稀释至60mL，稀释后溶液物质的量浓度为

12mol/L×10mL
60mL
=2mol/L，

故答案为：2mol/L；

（2）取（1）所配制的稀盐酸50mL，n（HCl）=0.05L×2mol/L=0.1mol，反应后最终溶液为NaCl溶液，溶液中n（Na+）=n（NaCl）=n（HCl）=0.1mol，

故答案为：0.1mol．

单项选择题

Walking through my train yesterday, staggering from my seat to the buffet and back, I counted five people reading Harry Potter novels. Not children-these were real grown-ups reading children’s books,
Maybe that would have been understandable. If these people had jumped whole-heartedly into a second childhood it would have made more sense. But they were card-carrying grown-ups with laptops and spreadsheets returning from sales meetings and seminars. Yet they chose to read a children’s book.
I don’t imagine you’ll find this headcount exceptional. You can no longer get on the London Tube and not see a Harry Potter book. Nor is it just the film; these throwback readers were out there in droves long before the movie campaign opened.
So who are these adult readers who have made JK Rowling the second-biggest female earner in Britain (after Madonna) As I have tramped along streets knee-deep in Harry Potter paperbacks, I’ve mentally slotted them into three groups.
First come the Never-Readers, whom Harry has enticed into opening a book. Is this a bad thing Probably not. Writing has many advantages over film, but it can never compete with its magnetic punch. If these books can re-establish the novel as a thrilling experience for some people, then this can only be for the better. If it takes obsession-level hype to lure them into a bookshop. that’s fine by me. But will they go on to read anything else Again, we can only hope.
The second group are the Occasional Readers. These people claim that tiredness, work and children allow them to read only a few books a year. Yet now—to be part of the crowd, to say they’ve read it—they put Harry Potter on their oh-so-select reading list. It’s infuriating, and maddening. Yes, I’m a writer myself, currently writing difficult, unreadable, hopefully unsettling novels, but there are so many other good books out there, so much rewarding, enlightening, enlarging works of fiction for adults; and yet these sad cases are swept along by the hype, the faddism, into reading a children’s book.
The third group are the Regular Readers, for whom Harry is sandwiched between McEwan (英国当代作家) and Balzac, Roth (德国现代诗人) and Dickens. This is the real baffler—what on earth do they get out of reading it Why bother But if they call rattle through it in a week just to say they ve been there—like going to Longleat (朗利特山庄英国名胜) or the Eiffel Tower—the worst they’re doing is encouraging others.

The word "infuriating" underlined in Paragraph 6 is closest in meaning to ______.

A．vexing

B．angry

C．displeasing

D．unhappy
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问答题 简答题

自动空气开关有哪几部分组成？
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