问题 问答题

利用下列仪器进行气体的制取和性质实验。请完成下列问题。

⑴仪器B的名称是                   

⑵实验室制取二氧化碳,从上述仪器中组合1套发生装置为                 (填字母)。

(3)在B中收集满二氧化碳,倒扣于盛有水的H中,一段时间后,B中液面__________(填“上升”或“不变”)。

答案

(1)试管。(2)A 、  D、  E(填字母)。 (3)上升

题目分析:(1)根据常用仪器可知,B是试管;

(2)制取气体的发生装置,是由反应物的状态和反应的条件决定的,实验室制取二氧化碳用的是石灰石或大理石固体和稀盐酸在常温下反应,故应选择“固液不加热型”装置来制取二氧化碳,容积较大的锥形瓶A可作为反应容器,为了便于随时添加液体药品,可选长颈漏斗D,当然,同时还要用到带导气管的双孔橡皮塞,故选A、D、E;

(3)用试管收集满二氧化碳,并倒扣于盛有水的水槽中,一段时间后,由于二氧化碳可溶于水,且能和水反应,故试管内的二氧化碳气体会减少,压强会随之减小,水槽中的水会在大气压的作用下进入试管,所以会看到试管中的液面会上升。

点评:常见气体的发生装置,依据反应物的状态和反应条件,可分为“固体加热型”和“固液常温型”两种装置;常用气体的收集装置,依据气体的溶解性、密度及其是否与水或者空气的成分发生反应,可分为“排水法”、“向下排空气法”、“向上排空气法”三种装置来收集。

阅读理解

C

Patients and doctors alike have long believed in the healing (治疗) power of humor. It is claimed that humor not only affects patients’ moods, but can actually help them recover faster.

Several studies seem to support this. Patients in better spirits are known to have higher immune cell counts. Some have even claimed to have healed themselves of serious illnesses by reading comics and watching comedies.

Despite all this, many researchers are not convinced. They point out the fact that many sufferings have been known to disappear naturally, with or without a daily dose of laughter. They also say that while optimism in general does seem to be related to better health, it is hard to tell which comes first.

Humor in times of stress, however, clearly makes us feel better. On one level, it takes our minds off our troubles and relaxes us. On another, it releases powerful endorphins, a chemical produced by your body that reduces pain.

There are cases where the appreciation of a good joke is indeed directly related to a person’s health. It can show, for example, whether a person has suffered damage to one particular area of the brain: the right frontal lobe (额叶).

Scientists confirmed this by having people read jokes and asking them to choose the funniest endings from a list. Subjects with normal brains usually chose endings that were based on a relatively complex synthesis (综合) of ideas. Subjects with specifically located brain damage, however, responded only to slapstick (闹剧) endings, which did not depend on a particular context. When pressed, the brain-damaged subjects saw the logic in the correct endings. They simply did not find them funny.

Of course, humor is largely an individual matter. Next time your friend does not get one of your jokes, there is no need to accuse him of being a lamebrain. However, you might suggest that he lighten up—for the health of it.

63. We can infer from the passage that ________.

A. all researchers have agreed on the healing power of humor

B. people seldom accuse their friends of not understanding jokes

C. the author holds a positive attitude to the healing power of humor

D. reading comics will surely become a popular way of treating diseases

64. Which of the following statements is NOT true?

A. Many researchers are not convinced of the healing power of humor.

B. Patients in bad moods are known to have higher immune cell counts.

C. Optimism in general does seem to be related to better health.

D. People should try their best to cheer up for their good health.

65. Scientists had some people read jokes and asked them to choose the funniest endings from a list to confirm that ________.

A. the brain-damaged people are different from those with normal brains

B. a person with a normal brain usually responds to slapstick endings

C. a person suffering certain brain damage doesn’t appreciate a good joke

D. humor takes our minds off our troubles by releasing powerful endorphins

66. Which would be the best title for the passage?

A. Which comes first, humor or health?             B. Humor can cure different illnesses

C. People need humor in times of stress        D. Humor contributes to good health

判断题