问题 问答题

下图是实验室常用的实验装置:

请回答下列问题:

(1)用B装置制取气体应具备的反应物的状态和反应条件是______.

(2)装置A除了可制取H2外,还可用于制取______气体.

(3)实验室若用锌和稀盐酸制取氢气,欲得到纯净、干燥的H2,选用装置的连接顺序为______,其中D装置的作用是______.

(4)若用木炭粉还原氧化铜并验证其产物,应将B装置稍作改进,其方法是______,写出B装置中发生反应的化学方程式______.

答案

(1)用B装置制取气体,根据图示,故答案为:反应物均应为固体且反应需要加热;

    (2)装置A使用于固态物质和液态物质反应不需加热的发生装置,可用来制H2(可由锌粒和稀硫酸反应制得)或CO2(可由大理石或石灰石与稀盐酸反应制得) 或 O2(可由过氧化氢溶液反应、二氧化锰作催化剂制得); 故答案为:CO2(二氧化碳或O2).

   (3)实验室若用锌和稀盐酸制取氢气时,因盐酸易挥发,所以制得的氢气内混有少量HCl气体和水蒸气,欲得到纯净、干燥的H2,必须先用装置D除掉HCl气体再用装置C除掉水蒸气后用装置E收集(氢气密度最小),因为装置D内盛的是氢氧化钠溶液能很快吸收HCl气体发生化学反应.故答案为:ADCE  吸收氢气中混有的HCl气体.

   (4)若用木炭粉还原氧化铜需高温反应,所以将酒精灯改为酒精喷灯(或在酒精灯火焰上加网罩),验证其产物需将导管通入澄清的石灰水中,观察石灰水是否变浑浊.B装置中发生反应的化学方程式为:C+2CuO

 高温 
.
 
2Cu+CO2↑,故答案为:将酒精灯改为酒精喷灯(或在酒精灯火焰上加网罩)、将导管通入澄清的石灰水中、C+2CuO
 高温 
.
 
2Cu+CO2

故答案:

(1)反应物均为固体且反应需要加热

(2)CO2(二氧化碳或O2

(3)ADCE吸收氢气中混有的HCl气体

(4)将酒精灯改为酒精喷灯(或在酒精灯火焰上加网罩)将导管通入澄清的石灰水中C+2CuO

 高温 
.
 
2Cu+CO2

完形填空

Nowadays,studying abroad is popular in China with many rich parents. They would rather send their children abroad to receive education in English-speaking countries than let them be educated in China.

As every coin has two sides,studying abroad is the same.There are advantages for people to attend schools abroad. In the first place,he can use English in his daily life to improve his English greatly,as it is obvious that there is no better chance to improve English than living in the country where it is spoken. While studying in a foreign country,it is possible to make friends from all over the world. This is not only exciting on the social level,but could lead to important overseas contacts in his career as well. He can get familiar with the latest knowledge in science and make use of the best facilities available. In this way, he is able to widen his horizon and broaden his mind.

Of course,attending schools abroad may bring about a series of problems. The most serious problem is language barrier.Most of the students who go abroad don’t have enough skills in the language spoken there. As a result,on arriving there,they will find it difficult to understand what the teachers say. Besides,for lack of knowledge of the customs of the local people,they may constantly run into trouble in dealing with various situations.

In conclusion,given an opportunity to attend a school abroad,one must consider both sides of the factors carefully before making up his mind.

小题1: List two advantages of studying abroad.

小题2: What is the most serious problem of studying abroad?

小题3: What’s the passage mainly about?

单项选择题