问题 实验题

下图所示为常见气体制备、分离、干燥和性质验证的部分仪器装置(加热设备及夹持固定装置均略去),请根据要求完成下列各题(仪器装置可任意选用,必要时可重复选择,a、b为活塞)。

(1)若气体入口通入CO和CO2的混合气体,E内放置CuO,选择装置获得纯净干燥的CO,并验证其还原性及氧化产物,所选装置的连接顺序为___________ (填代号)。能验证CO氧化产物的现象是___________________________________。

(2)停止CO和CO2混合气体的通入,E内放置Na2O2,按A→E→D→B→H装置顺序制取纯净干燥的O2,并用O2氧化乙醇。此时,活塞a应________,活塞b应_________,需要加热的仪器装置有___________(填代号),m中反应的化学方程式为______________________________。

(3)若气体入口改通空气,分液漏斗内改加浓氨水,圆底烧瓶内改加NaOH固体,E内放置铂铑合金网,按A→G→E→D装置顺序制取干燥氨气,并验证氨的某些性质。

①装置A中能产生氨气的原因有:____________________________。

②实验中观察到E内有红棕色气体出现,证明氨气具有___________性。

答案

(1)ACBECF;AB之间的C装置中溶液保持澄清,EF之间的C装置中溶液变浑浊

(2)关闭;打开;k、m;2CH3CH2OH+O22CH3CHO+2H2O

(3)①氢氧化钠溶于水放出大量热,温度升高,使氨的溶解度减小而放出,氢氧化钠吸水,促使氨放出,

氢氧化钠电离出的OH-增大了氨水中OH-浓度,促使氨水电离平衡左移,导致氨气放出;

②还原。

阅读理解

阅读理解。

     Four people in England, back in 1953, stared at Photo 51. It wasn't much–a picture showing a black X.

But three of these people won the Nobel prize for figuring out what the photo really showed—the shape of

DNA. The discovery brought fame and fortune to scientists James Watson, Francis crick, and Maurice

Wilkins. The fourth, the one who actually made the picture, was left out.

     Her name was Rosalind Franklin. "she should have been up there," says historian Mary Bowden. "if her

photo hadn’t been there, the others couldn’t have come up with the structure." One reason Franklin was

missing was that she had died of cancer four years before the Nobel decision. But now scholar doubt that

Franklin was not only robbed of her life by disease but robbed of credit by her competitions.

     At Cambridge university in the 1950s, Watson and Crick tried to make models by cutting up shapes of

DNA’s parts and then putting them together. In the meantime, at king’s college in London, Franklin and

Wilkins shone X-rays at the molecule (分子). The rays produced patterns reflecting the shape.

     But Wilkins and Franklin’s relationship was a lot rockier than the celebrated teamwork of Watson and

Crick. Wilkins thought Franklin was hired to be his assistant. But the college actually employed her to take

over the DNA project.

     What she did was produce X-ray pictures that told Watson and Crick that one of their early models was

inside out. And she was not shy about saying so. That angered Watson, who attacked her in return, "Mere

inspection suggested that she would not easily bend. Clearly she had to go or be put in her place."

     As Franklin's competitors, Wilkins, Watson and Crick had much to gain by cutting her out of the little

group of researchers, says historian Pnina Abir-Am. In 1962 at the Nobel prize awarding ceremony, Wilkins

thanked 13 colleagues by name before he mentioned Franklin. Watson wrote his book laughing at her. Crick

wrote in 1974 that "Franklins was only two steps away from the solution."

     No, Franklin was the solution. "She contributed more than any other player to solving the structure of

DNA. She must be considered a co-discoverer," Abir-Am says. This was backed up by Aaron Klug, who

worked with Franklin and later won a Nobel Prize himself. Once described as the "Dark Lady of DNA",

Franklin is finally coming into the light.

1. What is the text mainly about?

A. The disagreements among DNA researchers.

B. The unfair treatment of Franklin.

C. The process of discovering DNA.

D The race between two teams of scientists.

2. Watson was angry with Franklin because she _____.

A. took the lead in the competition

B. kept her results from him

C. proved some of his findings wrong

D. shared her data with other scientists

3. Why is Franklin described as "Dark Lady of DNA"?

A. She developed pictures in dark labs.

B. She discovered the black X—the shape of DNA.

C. Her name was forgotten after her death.

D. Her contribution was unknown to the public.

4. What is the writer's attitude toward Wilkins, Watson and Crick?

A. Disapproving    

B. Respectful   

C. Admiring          

D. Doubtful

单项选择题