问题 填空题

二氯化二硫(S2Cl2)在工业上用于橡胶的硫化.为在实验室合成S2Cl2,某化学研究性学习小组查阅了有关资料,得到如下信息:

①将干燥的氯气在110℃~140℃与硫反应,即可得S2Cl2粗品.

②有关物质的部分性质如下表:

物质熔点/℃沸点/℃化学性质
S112.8444.6
S2Cl2-77137遇水生成HCl、SO2、S;300℃以上完全分解;S2Cl2+Cl2
  △  
.
 
2SCl2
设计实验装置图如下:

(1)上图中尾气处理装置不够完善,请你提出改进意见______.利用改进后的正确装置进行实验,请回答下列问题:

(2)B中反应的离子方程式______.

(3)C中的试剂是______.F的作用是______.

(4)如果在加热E时温度过高,对实验结果的影响是______,在F中可能出现的现象是______.

(5)为了提高S2Cl2的纯度,关键的操作是控制好温度和______.

答案

(1)①G收集产品,H中氢氧化钠溶液中水蒸气易挥发,进入G中,易使S2Cl2水解.在G和H之间增加干燥装置.

②若B中气压过大,A中浓盐酸不容易滴下,A与B之间应接一根导管,使A与B内气压相平衡,浓盐酸在重力作用下顺利滴入烧瓶.故答案为:在G和H之间增加干燥装置.

(2)用固液加热的方法制Cl2,常用浓盐酸和二氧化锰反应制取,反应离子方程式为MnO2+4H++2Cl-

  △  
.
 
Mn2++Cl2↑+2H2O.

故答案为:MnO2+4H++2Cl-

  △  
.
 
Mn2++Cl2↑+2H2O.

(3)氯气中氯化氢用饱和食盐水吸收,用浓硫酸干燥,先除氯化氢,后干燥.故C中试剂饱和食盐水(或水).F导管较长有两个作用:导出产品和冷凝产品.导气、冷凝.

故答案为:饱和食盐水;导气、冷凝.

(4)产品热稳定性差,温度过高,产品部分生成了二氯化硫,产率偏低.根据硫的熔点和沸点知,温度过高,使部分硫变成蒸汽,而硫的熔点较低,易凝固,导致堵塞F管.

故答案为:产率降低(或S2Cl2分解);有固体产生.

(5)由信息可知,可能因温度、水蒸气因素引入HCl,S,SO2,SCl2杂质.若滴加盐酸过快,部分水蒸气没有被硫酸吸收,导入E管中.故应控制浓盐酸的滴速不要过快.

故答案为:控制浓盐酸的滴速不要过快.

单项选择题
单项选择题

You might guess that experienced drivers have fewer accidents, but research from insurer AXA has revealed that they are more law-abiding and honest, too. A poll of 2 000 drivers in the UK found that those who have been behind the wheel for eight years or more had not only caused half as many accidents in the last year as less experienced drivers, but were also less likely to have broken the law or lied to their insurer.

Experienced drivers were half as likely to have been caught using a mobile phone while driving within the last year; and a third as likely to have been caught driving under the influence of alcohol or drugs, or to have been convicted of dangerous driving. They were also a fifth as likely to have been convicted of driving without a seatbelt.

Dishonest behavior appears to be much more common among newer drivers. The UK’s experienced drivers have always been an attractive group for insurers, but the much lower risk they present is rarely fully reflected in their premiums. This is why AXA has entered the direct car insurance market with a product that rewards them with a no-claims discount of up to 90 percent--far higher than anything else on the market. Only those drivers who have been claim-free for eight years or more will be eligible, which could offer large savings for around a third of motorists.

AXA’s research has enabled it to tailor not only the pricing to these expert drivers, but the service, too. AXA Car Insurance will offer a courtesy ear whenever yours is out of action due to accident, fire or theft, not just while it’s being repaired. The survey found they wanted higher service levels too, so customers will be able to change their policy details online or track a claim at any hour of the day or night, every day of the year.

Many drivers wrongly assumed they were insured if they were injured in accidents that are their faults. To plug the gap, AXA has introduced Driver Injury Cover,which pays up to £1 million for medical treatment and loss of earnings for an additional annual premium of £34.99--less than £3 a month.

Cocky newer drivers do appear to be somewhat overconfident. A third of those who’d been on the road for between only one and two years claimed they were already experienced drivers, and that rose to a half among those who’d been driving for just one more year. But, as AXA’s survey demonstrates, they have still got a lot to learn., they will need to be driving for at least five more years before they can take advantage of that 90 per cent no-claims discount.

According to the first paragraph, we can learn that "those who have been behind the wheel" are()

A. managers

B. researchers

C. guides

D. drivers