问题 问答题

在实验室制取氧气的实验中,小军与同学们选择了如图所示的仪器和装置,欲利用过氧化氢为原料来制取氧气.请你参与他们的实验,并回答有关问题:

(1)指出图中仪器的名称:

a______,b______,c______,d______.

(2)小军欲在装置A中①处添加a仪器或b仪器,作用是______.他认为使用a仪器比b仪器好,a仪器的优点是______.

(3)A装置中发生反应的化学方程式为______.

(4)实验中采用的收集气体的方法为______,能采用此法收集氧气的理由是______;收集氧气还可以采用的方法是______,理由是______.

(5)证明B中氧气已收集满的方法是______.

(6)在实验室中利用此装置还可以制取和收集的另一种气体是______,试写出该气体与澄清石灰水反应化学方程式为______.

答案

(1)图中仪器分别是分液漏斗、长颈漏斗、锥形瓶、集气瓶;

(2)可用分液漏斗和长颈漏斗向容器中添加液体,分液漏斗可控制滴加液体的速度,从而控制反应速率,并且可以控制药品的量,节约药品;

(3)过氧化氢在二氧化锰的催化作用下分解生成水和氧气,反应方程式是:2H2O2

 MnO2 
.
 
2H2O+O2↑;

(4)图示所用收集方法集气瓶口向上,是向上排空气法,氧气的密度比空气大,故可用此法收集;氧气不易溶于水,还可用排水法收集;

(5)利用排空气法收集氧气时,可用带火星的木条放于集气瓶口,观察木条是否复燃判断是否收集满;

(6)该装置适用于固体和液体常温制取气体,且收集的气体密度比空气大,实验室制取二氧化碳用大理石和稀盐酸常温反应可用此发生装置,二氧化碳的密度比空气大,故可用向上排空气法收集,检验二氧化碳用澄清的石灰水,反应方程式是:Ca(OH)2+CO2═CaCO3↓+H2O;

故答案为:(1)分液漏斗、长颈漏斗、锥形瓶、集气瓶;

(2)向锥形瓶中加入过氧化氢溶液;可以控制滴加液体的速度并且可以控制药品的量,节约药品;

(3)2H2O2

 MnO2 
.
 
2H2O+O2↑;

(4)向上排空气;密度比空气大;排水法;氧气不易溶于水;

(5)将带火星的木条放于集气瓶口,若木条复燃证明已收集满;

(6)二氧化碳;Ca(OH)2+CO2═CaCO3↓+H2O.

单项选择题
单项选择题

Now which are the animals really to be pitied in captivity First, those clever beings whose lively urge for activity can find no outlet behind the bars of the cage. This is most conspicuous, even for the uninitiated, in the case of animals which, when living in a free state, are accustomed to roaming about widely. Owing to this frustrated desire, foxes and wolves housed, in many old-fashioned zoos, in cages which are far too small, are among the most pitiable of all caged animals.
Though pinioned swans generally seem happy, under proper care, by hatching and rearing their young without any trouble, at migration time things become different: they repeatedly swim to the lee side of the pond, in order to have the whole extent of its surface at their disposal, trying to take off. Again and again the grand preparations end in a pathetic flutter of their half wings ; a truly sorry picture !
This, however, rarely awakens the pity of the zoo visitor, least of all when such an originally highly intelligent and mentally alert animal has deteriorated, in confinement, into a crazy idiot, a very caricature of its former self. Sentimental old ladies, the fanatical sponsors of the societies for Prevention of Cruelty to Animals, have no compunction in keeping a grey parrot in a relatively small cage or even chained to a perch. Together with the large corvines, the parrots are probably the only birds which suffer from that state of mind, common to prisoners, namely, boredom.

Which is the "lee side" of the pond

A. The side the wind is blowing from.
B. The side which is sheltered from a storm.
C. The side the wind is blowing towards.
D. The side where the water is the deepest.