问题 填空题

大多金属碳化物能与水剧烈反应,生成相应氢氧化物和气态烃,如:

Na4C+4H2O→4NaOH+CH4↑ MgC2+2H2O→Mg(OH)2+C2H2

现有CaC2与某常见主族金属碳化物A的混合物,与足量盐酸反应,得一澄清溶液,并有大量气体产生,将气体通过碱石灰干燥除杂后,测其体积为V1,将所得气体充分燃烧,生成的CO2的体积为V2,相同条件下,V1:V2=5:7;向澄清溶液中逐渐加入足量Na2CO3溶液后,再继续加入NaOH溶液,沉淀物质的量变化如下图所示,试回答下列问题:

(1)已知A中的金属元素是短周期元素,则该元素是:__________(写元素符号),写出CaC2与浓盐酸反应的化学方程式:____________________;

(2)根据V1:V2=5:7,可算出混合烃中平均每1mol 烃分子含有_______molC,由此可知气态混合烃中含有乙炔和______________;

(3)A的化学式为________;

(4)原混合物中CaC2的物质的量为________mol,A的质量为______g

答案

(1) Al;CaC2+2HCl→CaCl2+C2H2

(2) 1. 4;甲烷

(3)Al4C3

(4)0.4;28.8

阅读理解

Staying positive through the cold season could be your best defense against getting ill, new study findings suggest.

In an experiment that exposed healthy volunteers to a cold or flu virus, researchers found that people with a generally sunny character were less likely to fall ill. The findings, published in the journal Psychosomatic Medicine, build on evidence that a “positive emotional style” can help to protect us from suffering the common cold and other illnesses.

Researchers believe the reasons may be both objective — as in happiness improving immune function — and subjective — as in happy people being less troubled by a sore throat or runny nose. “People with a positive emotional style may have different immune responses to the virus,” explained lead study author Dr Sheldon Cohen of Carnegie Mellon University in Pittsburgh. “And when they do get a cold, they may interpret their illness as being less severe.”

Cohen and his colleagues had found in a previous study that happier people seemed less likely to catch a cold, but some questions remained as to whether the emotional style itself had the effect.

For the new study, the researchers had 193 healthy adults complete standard measures of personality characteristics, self-felt health and emotional style. Those who had a tendency to be happy, energetic and easy-going were judged as having a positive emotional style, while those who were often unhappy, tense and aggressive had a negative style.

The researchers gave them nasal (鼻腔的) drops containing either a cold virus or a particular flu virus. Over the next six days, the volunteers reported on any aches, pains or sneezing they had, while the researchers collected objective data. Cohen and his colleagues found that based on objective measures of nasal troubles, happy people were less likely to develop a cold.

小题1:Which is the best title for the passage? ______

A.Stay Away from Being Negative

B.Positive or Negative?It’s Up to You.

C.Emotional Style and Flu.

D.Optimistic People Likely to Keep Diseases Away.小题2: According to Dr Cohen’s research, the reason why some people are unlikely to catch a cold may be that ______.

A.their cheerful mood benefits the immune system

B.they have developed a certain way against flu virus

C.they are less likely to have a sore throat and runny nose

D.they have got a stronger self-confidence in their health小题3: The research is done by ______.

A.getting volunteers in one emotional group and analyzing them

B.conducting a medical experiment on volunteers of different emotional styles

C.collecting and analyzing volunteers’ objective nasal production data

D.having volunteers answer questions on personality, health and emotions

多项选择题