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问题 问答题

工业接触法制硫酸的流程如图所示：

（1）写出沸腾炉中发生反应的化学方程式：______．

（2）从沸腾炉出来的气体经净化干燥处理后进入接触室，其气体体积组成：SO2 7%，O2 11%，N2 82%．从接触室出来的气体中SO3 的体积分数为7%，则SO2的转化率为______．

（3）接触室采用常压而不采用高压的原因是______．

（4）在吸收塔中用98.3%的浓硫酸吸收SO3 ，而不是用水吸收SO3 的原因是______．

每100g SO3 与H2O完全反应放出热量162.9kJ，该反应的热化学方程式为______．

（5）某硫酸厂每天用含FeS2 60%的黄铁矿500t生产硫酸，如果在沸腾炉内损失5%的硫，SO2 的转化率为90%．每天能生产98%的硫酸______t．

答案

（1）FeS2与O2在高温条件下生成Fe2O3和SO2，故答案为：4FeS2+11O2

 高温 
.
 
2Fe2O3+8SO2；

（2）设总体积为100

2SO2+O2=2SO3

初始 7 11 0

转化 x

1
2
x x

平衡 7-x 11-

1
2
x x

x
7-x+11-
1
2
x+x+82
=7%

x=

1400
207

转化率=

x
7
×100%=96.6%，故答案为：96.6%；

（3）常压时SO2的转化率已经很高，采用高压对SO2的转化率提高不多，却会大大增加设备成本，故答案为：常压时SO2的转化率已经很高，采用高压对SO2的转化率提高不多，却会大大增加设备成本；

（4）△H=-

162.9KJ×80g/mol
100g
=-130.3KJ/mol，故答案为：SO3（g）+H2O（l）=H2SO4（l）△H=-130.3KJ/mol；

（5）沸腾炉中损失5%的硫，SO2转化率为90%这些都可转化为S元素的损失，进而转化为FeS2的损失．所以设生产98%的硫酸x吨．则由关系式：

           FeS2------------2H2SO4                 

           120               2×98

  500t×60%×（1-5%）×90%   x×98%                 

解得  x=427.5t，

故答案为：427.5．

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Libraries everywhere in the world have always been people’s only access to important sources of information.  This historical function of libraries has worked out for centuries and has made libraries a necessity to people.  Now, that function has been called into question by the fast development of digital media over the past several decades. In order to continue to hold the public interest, libraries everywhere are forced to develop means of granting access to these expensive new services to average people.

In the past, the publishing industry maintained the rights of libraries to freely provide published materials on the condition that libraries bought so many of their books. Since the new electronic publications can easily be copied in their completeness by the library readers, the publishing industry is reconsidering its former support of the library system. There have even been attempts to stop libraries from delivering digital media.

In addition to the reluctant cooperation of the publishing industry, there is the problem that the newer forms of information are much more specialized than those which they replace. Deciding how to transfer already limited resources is increasingly difficult as there are more methods. While a single reference index(索引) might have covered an entire field in the past, now there are frequently several specialized indexes available in electronic form. Above all, in order to continue to make use of the newer technology, libraries must decide which kinds of material are most useful to the majority of their readers. There are many different solutions being applied, but only the process of trial and error will help find out the most effective method.

（Note: Answer the questions or complete the statements in NO MORE THAN 20 WORDS）

1. What has been called into question?

2. In the past, publishers cooperate with libraries because ______________.

3. The most important way to use the new technology is to determine ________

4. According to the passage, how can best solutions be found?

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