问题 选择题

下列各组物质在给定条件下能大量共存的是(  )

A.在pH=1的溶液中:KNO3、K2CO3、K2SO4

B.在pH=2的溶液中:NH4NO3、Na2SO4、HCl

C.在pH=13的溶液中:BaCl2、NaOH、Na2CO3

D.在pH=14的溶液中:CuSO4、NaNO3、NaCl

答案

A、pH为1的水溶液显酸性,水溶液中含有大量的H+,K2CO3中的碳酸根离子和和H+在溶液中能结合生成水和二氧化碳,不能大量共存,故选项错误.

B、pH为2的水溶液显酸性,水溶液中含有大量的H+,三者之间不反应,能在酸性溶液中共存,故选项正确.

C、pH为13的水溶液显碱性,水溶液中含有大量的OH-,BaCl2与Na2CO3在溶液中能相互交换成分生成碳酸钡沉淀和氯化钠,不能大量共存,故选项错误.

D、pH为14的水溶液显碱性,水溶液中含有大量的OH-,CuSO4中的铜离子和和OH-在溶液中能结合生成氢氧化铜沉淀,不能大量共存,故选项错误.

故选B.

阅读理解

Recently, Chinese netizens (网民) enjoy themselves on “growing and stealing crops” on the Internet. This is a game called “Happy Farms”. Now more and more people are joining in the game, and getting addicted. Some of them are even found playing the game at work. Because of this, some players have been fired by their bosses. Lovers have broken up, but none of them can stop Happy Farms from becoming more popular.

Here we interviewed some young netizens and let’s see what their opinions were.

Nongmin: Playing happy Farms at work, that’s terrible! A clerk was fired because she was online playing it at work.

King: I find that all the dreams of having houses and fields, which are very hard to get in real life, are very easy to be realized in the games. I think I know the reason why the game is so popular.

Kaixin: We have to know how to control ourselves. We should keep our minds on study. Games are just games. I prefer to play sports with my classmates when I am free.

Kitty: I like Happy Farms. My high-pressure work makes me feel like I can’t breathe. I wish I could have a real house and farm, but it seems so far away. I have to turn to virtual(虚拟) nature for my own house and farm.

People often get tired from work or study, so they go to their own farms, take care of their crops and pull out weeds. It is really delightful to forget about the pressure. But some players work from morning to night to “grow and steal crops”. They lose themselves in the game and show no interest in anything else. It is really terrible.

小题1:From this passage, we know that “Happy Farms” is _____.

A.a popular online game

B.a kind of sport

C.an interesting online film

D.a real farm小题2:The word “fire” means _____ in the underlined sentence in the first paragraph.

A.火

B.雇佣

C.解雇

D.着火小题3: From Kaixin’s words, we can guess that he is probably a_____.

A.farmer

B.worker

C.student

D.clerk小题4:_____ have the similar idea about “Happy Farms”.

A.Nongmin and King

B.King and Kitty

C.Kaixin and Kitty

D.Nongmin and Kaixin小题5: From the passage, the writer thinks _____.

A.“Happy farms” is good for people’s work and study

B.people can play “Happy farms” at night

C.people should never play “Happy farms”

D.“Happy farms” sometimes can help you relax but it may also cause problems

判断题