问题 问答题

下图是实验室用于制取、干燥和收集气体的装置图.

(1)若用装置A制取氧气,装置中放入的药品为:______ 和______.

(2)若用装置B制取氧气,写出一个反应的化学方程式:______.

(3)若想用排水法收集干燥的氧气(C中盛满水),则装置端口连接顺序是

a______→______→______→______→______.

答案

(1)发生装置A用于固体与液体发生反应,因此选用该装置制取氧气时,装置内所加入的药品应为液体过氧化氢溶液和固体催化剂二氧化锰;

(2)发生装置B用于对固体加热制取气体的反应,因此选用该装置制取氧气时,应选用加热分解高锰酸钾或在二氧化锰催化下加热分解氯酸钾制取氧气,发生反应的化学方程式为2KClO3

MnO2
.
2KCl+3O2↑或2KMnO4
  △  
.
 
K2MnO4+MnO2+O2↑;

(3)从导管a排出的气体通入浓硫酸时,氧气应从伸入液面以下的b导管进入,这样可充分吸收气体中所含有的水;然后将从b管排出被干燥了的氧气通入装满水的装置C中,为排出瓶内的水,氧气应从伸入较短的e导管进入而使瓶内水由导管d排出,从而完成氧气的收集.

故答案为:

(1)过氧化氢(或H2O2),二氧化锰(或MnO2);

(2)2KClO3

MnO2
.
2KCl+3O2↑(或2KMnO4
  △  
.
 
K2MnO4+MnO2+O2↑);

(3)b,c,e,d.

多项选择题
阅读理解
Thinking
·Some scientists claim that we humans are the only living things that are conscious(有意识的)—we alone are aware that we are thinking.
·No one knows how consciousness works—it is one of science’s last great mysteries.
·All your thoughts take place in the cerebrum(大脑皮质),which is at the top of your brain,and different kinds of thought are linked to different areas,called association areas.
·Each half of the cerebrum has four rounded ends called lobes(脑叶)—two at the front(frontal and temporal lobes)and two at the back(occipital and parietal lobes).
·The frontal lobe is linked to your personality and it is where you have your bright ideas.
·The temporal lobe is where you hear and understand what people say to you.
·The occipital lobe is where you work out what your eyes see.
·The parietal lobe is where you record touch,heat and cold,and pain.
·The left half of the brain controls the right side of the body.The right half controls the left side.
·One half of the brain is always dominant(in charge).Usually,the left brain is dominant,which is why 90% of people are right-handed.
小题1:Which part of your cerebrum is most active when you are making a telephone call?
A.The frontal lobe.B.The temporal lobe.
C.The occipital lobe.D.The parietal lobe.
小题2:Which of the following statements is true?
A.One’s personality has something to do with the frontal lobe.
B.Bright ideas come from the parietal lobe.
C.The occipital and temperal lobes are at the back of the cerebrum.
D.The occipital lobe is in charge of sound.
小题3:From the passage,we know the reason why around 10% of people are left-handed is that_______.
A.their frontal lobe is usually dominant
B.their temporal lobe is usually dominant
C.their right brain is usually dominant
D.their left brain is usually dominant