问题 问答题

在煤中加入适量的生石灰(CaO)制成供居民采暖用的“环保煤”,以减少二氧化硫的排放,减弱二氧化硫对空气的污染.燃烧时生石灰吸收二氧化硫的化学方程式为:2CaO+mSO2+O2

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mCaSO4请回答下列问题:

(1)m值是______;

(2)该反应属于基本反应类型中的______

(3)若煤厂一次共加入含氧化钙80%的生石灰1400 吨,则理论上最多可吸收二氧化硫多少吨?

答案

(1)观察方程式2CaO+mSO2+O2

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mCaSO4,反应前有2个钙原子,则反应后也应有2个钙原子,所以m=2;

(2)该反应是由三种物质生成一种物质,属于化合反应;

(3)含氧化钙80%的生石灰中含氧化钙1400t×80%=1120t

设理论上最多可吸收二氧化硫的质量为x

2CaO+2SO2+O2

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2CaSO4

112   128

1120t x

112
1120t
=
128
x
 

     x=1280t

故答案为:(1)2;(2)化合反应; (3)加入含氧化钙80%的生石灰1400t,最多可吸收二氧化硫的质量为1280t.

阅读理解

In the old days, children were familiar with birth and death as part of life. Now this is perhaps the first generation of American youngsters who have never been close by during of the birth a baby and have never experienced the death of a family member.

Nowadays when people grow old, we often send them to nursing homes. When they get sick, we send them to a hospital, where children are forbidden to visit terminally (晚期的)in patients— even when those patients are their parents. This deprives(剥夺)the dying patient of family members during the last few days of his life and it deprives the children of an experience of death, which is an important learning experience.

Some of my colleagues and I once interviewed and followed about 500 terminally in order to find out what they could teach us and how we could be of more benefit, not just to them but to the members of their families as well. We were most impressed by the fact that even those patients who were not told of their serious illness were quite aware of its potential outcome.

It is important for family members, and doctors and nurses to understand these patients’ communication in order to truly understand their needs, fears and fantasies . Most of our patients welcomed another human being with whom they could talk openly, honestly, and frankly about their trouble. Many of them shared with us their great need to be informed, to be kept up - to - date on their medical condition and to be told when the end was near. We found out that patients who had been dealt with openly and frankly were better able to cope with the coming of death and finally to reach a true stage of acceptance before death.

小题1: The elders of today's Americans _______ .

A.are often absent when a family member is born or dying

B.are unfamiliar with birth and death

C.usually see the birth or death of a family member

D.have often experienced the fear of death as part of life小题2: Children in America are deprived of the chance to________.

A.visit a patient at hospital

B.visit their family members

C.learn how to face death

D.look after the patients小题3: The need of a dying patient for people to accompany him shows________.

A.his wish for communication with other people

B.his fear of death

C.his unwillingness to die

D.he feels very upset about his condition小题4: It may be concluded from the passage that________.

A.dying patients should be truthfully informed of their condition

B.dying patients are afraid of being told of the coming of death

C.most patients are unable to accept death until it can’t be avoided

D.most doctors and nurses understand what dying patients need

判断题