问题 选择题

下列图像与所述实验相符的是

 

A                 B                  C                 D

A.向一定量锌粒中加入过量稀硫酸

B.向一定量氯化钠饱和溶液中不断加水

C.向一定量氢氧化钠和碳酸钠的混合溶液中加入过量的石灰水

D.20℃时,向一定量不饱和的硝酸钾溶液中加入过量的硝酸钾晶体

答案

答案:D

题目分析:把握具体反应时的物质量的关系,结合图像分析判断。

A、锌与稀硫酸反应生成硫酸锌和氢气,反应后的溶液为硫酸锌溶液;随硫酸质量增加,反应不断发生,溶液中硫酸锌的质量不断增加,溶液中硫酸锌的质量分数变大;当锌完全反应,溶液中硫酸锌的质量不再增加,而随硫酸的加入,溶液的质量继续变大,此时溶液中硫酸锌的质量分数会减小,而曲线中表示的溶液中的硫酸锌质量分数持续增大,不正确;

B、向一定量氯化钠饱和溶液中不断加水,由于溶质氯化钠的质量不变,而随着水的质量不断增加,溶液的质量增大,则溶液中的溶质质量分数将逐渐减小,但不可能为0,不正确;

C、向一定量氢氧化钠和碳酸钠的混合溶液中加入过量的石灰水,氢氧化钙与碳酸钠反应立即生成碳酸钙沉淀,且随石灰水不断加入,生成沉淀质量会不断增加,直到完全反应,生成沉淀质量不再增加,而曲线表示的是,在加入石灰水一定量后才会出现沉淀,与反应事实不符,不正确;

D、20℃时,向一定量不饱和的硝酸钾溶液中加入过量的硝酸钾晶体,硝酸钾晶体会不断溶解,故溶液的溶质质量分数会变大,当溶液达到饱和时,硝酸钾不再溶解,溶液的溶质质量分数也就不再改变,正确。故选D

点评:解答本题除了要掌握相关化学知识之外,还要能看懂图像,在讨论图象问题时,一定要分清图象中X、Y轴所表示的具体含义,因为变换了X、Y轴的内容,所对应的图象就会出现不同的情形。

阅读理解

根据短文内容,选择最佳选项。

     Last July, many newspapers carried a moving photo: a woman pushing a tricycle (三轮脚踏车) in the

rain. According to one of the newspapers, the woman is the head teacher of Hoping Primary School in

out-of-the-way Huaiyang County. Her name is Li Ling.

     At only 27, she was known as the most beautiful teacher of 2009. In 2002, after leaving school, she

set up a primary school in her hometown in order to help rural children get education. She has borrowed

more than 100,000 yuan for school facilities (设施) since then.

     Because the students couldn't afford books, she went to Zhengzhou during the summer vacation to buy

second-hand reading materials for them. She went alone, riding her tricycle through the streets under the

burning sun, with only one aim (目的)—to set up a simple "reading room" for 300 students.

     "Each time I see students from other schools sitting and reading in a bright reading room, I feel sad. I

also want to set up a reading room for my students, even the simplest one,"she said.

     She is a beautiful young rural teacher, and always ready to help her students. 

 1. In which season was the picture taken?

A. Spring.

B. Summer.

C. Autumn.

D. Winter.

2. At the age of _____, Li Ling set up a primary school in her hometown.

A. 17

B. 20

C. 22

D. 27

3. Which of the following has the same meaning as the underlined word "second-hand"?

A. Similar.

B. Popular.

C. Not new.

D. Not difficult.

4. Which of the following is TRUE, according to the passage?

A. The photo became well-known.

B. Li Ling set up the school to make money.

C. Li Ling is very rich.

D. Li Ling works in Zhengzhou City.

5. What does the writer think Li Ling is like?

A. Silly.

B. Smart.

C. Great.

D. Clever.

多项选择题