问题 选择题

某种一元酸(HA)溶液中加入一定量的一种强碱(MOH)溶液后,恰好完全反应,则有关反应后溶液的判断中一定正确的是                                                       

A.[A-]≤[M+]

B.[A-]≥[M+]

C.若反应生成的MA不水解,则[A-]>[OH-]

D.若反应生成的MA水解,则[A-]<[OH-]

答案

A、C

本题中的一元酸可能是强酸或弱酸。若是HA为一元强酸与强碱完全中和时,[A-]=[M+],若HA为一元弱酸与强碱完全中和生成的MA为强碱弱酸盐,由于A-发生部分水解反应,[A-]<[M+],故A选项结论[A-]≤[M+]正确,而B选项不正确。若反应生成的MA不水解,即MA为强酸强碱盐,它电离出的[A-]一定大于由水电离出的[OH-]浓度,C选项也正确。

若是反应生成的MA能发生水解,说明HA必然是弱酸,MA为强碱弱酸盐,A-将发生水解:A-+H2OHA+OH-,多数情况[A-]>[OH-],D选项的结论正相反。

阅读理解

I love it at night. It’s peaceful. And when it cools down I sometimes do some ironing. I don’t really care for it. I work full-time and too busy for most housework. I remember the old woman who taught me to iron. I was about 15 and somehow got a live-in job taking care of a woman who had been an able-bodied, healthy woman until the accident that caused her to be paralyzed(瘫痪).

The woman had an electric wheelchair. She could move her head and arms but not her hands or fingers. She had this clamp(夹子)attached to her arm and I’d have to open it and put a cup or a pencil in it and then she could move it. She would tell me how to do things. She would instruct me in great detail on the correct way to do things. Her home was perfect and beautiful. She would follow me around in her electric wheelchair to make sure I did everything exactly right. I’m sure she had been a perfect homemaker. She would have me fold everything, including socks and pillow cases. I would complain silently and wish terrible things on her. She taught me the right way to make the bed and tuck (塞)the corners. I know sometimes she’d get frustrated and impatient with me. I knew she wanted to grab it and do it herself. But she never yelled or scolded. Only insisted I do it right. I didn’t like it much, but I did it.

Today I can iron pretty well. I know where to start on a shirt, the right way to do the collar and sleeves. Now that I think about it, I don’t think she is an old lady. I think she might have been about my age now. Anyway, when I iron, I think of her and silently thank her for all the things I learned.

小题1:From the passage we can infer that the writer of the passage now is ________.

A.a housewife

B.a full-time worker

C.a clothes maker

D.a college student小题2:The writer used to take care of the lady because ______.

A.she wanted to learn how to do housework

B.she was a relative of the disabled woman

C.she wanted to earn some money while sleeping and eating there

D.she had to do something in return to the lady for her kindness小题3:When the lady taught the writer how to do housework, the little girl was ______.

A.eager to learn

B.unwilling to learn

C.forced to learn

D.careful to learn小题4:What’s the writer’s attitude towards the lady now?

A.Sympathetic

B.Fearful

C.Hateful

D.Grateful

填空题