问题 问答题

硫酸是用途广泛的化工原料,可作脱水剂、吸水剂、氧化剂和催化剂等.

(1)工业制硫酸铜的方法很多.

①方法一、用浓硫酸和铜制取硫酸铜.该反应的化学方程式是______,此法的最大缺点是______.

②方法二、用稀硫酸、铜和氧化铁制取硫酸铜,生产的主要过程如图所示:

稀硫酸、铜和氧化铁反应的化学方程式是______;向混合溶液中通入热空气的反应的离子方程式是______;由滤液得到无水硫酸铜的实验操作是______.

(2)氨法脱硫技术可吸收硫酸工业尾气中的二氧化硫,同时制得硫酸铵.主要的工艺流程如图所示:

①吸收塔中发生反应的化学方程式是______.

②有数据表明,吸收塔中溶液的pH在5.5~6.0之间,生产效率较高.当控制一定流量的尾气时,调节溶液的pH的方法是______.

答案

(1)①铜和浓硫酸加热反应生成硫酸铜、二氧化硫和水,反应的化学方程式为:Cu+2H2SO4(浓)═CuSO4+SO2↑+2H2O;反应生成的二氧化硫是污染环境的气体,产生了有污染的气体;故答案为:Cu+2H2SO4(浓)

 加热 
.
 
CuSO4+SO2↑+2H2O;产生了有污染的气体;

②依据流程转化图分析,铜需要硫酸和氧化铁反应生成的铁离子溶解生成铜离子,再通入空气氧化亚铁离子为铁离子,调节溶液PH使铁离子沉淀除去,得到硫酸铜溶液;加热蒸发浓缩结晶得到硫酸铜晶体;反应的离子方程式为:Fe2O3+6H+═2Fe3++3H2O、2Fe3++Cu═2Fe2++Cu2+(或Fe2O3+Cu+6H+═3H2O+2Fe2++Cu2+);通入空气的作用是氧气氧化亚铁离子为铁离子的反应,反应离子方程式为:4Fe2++4H++O2═4Fe3++2H2O;得到硫酸铜溶液加热蒸发得到硫酸铜晶体;加热、蒸发;

故答案为:Fe2O3+6H+═2Fe3++3H2O、2Fe3++Cu═2Fe2++Cu2+;4Fe2++4H++O2═4Fe2++2H2O;加热、蒸发;

(2)①依据流程图分析,吸收塔中发生反应是二氧化硫、一水合氧气反应生成硫酸铵和水,反应的化学方程式为:4NH3∙H2O+2SO2+O2═2(NH42SO4+2H2O;

故答案为:4NH3∙H2O+2SO2+O2═2(NH42SO4+2H2O;

②吸收塔中溶液的pH在5.5~6.0之间,生产效率较高.当控制一定流量的尾气时,调节溶液的pH的方法是,调节氨水的流量,故答案为:调节氨水的流量;

填空题
单项选择题

In the rarefied world of the corporate board, a good network matters. (1) often involves word-of- mouth recommendations: getting on a (2) is easier if you have the right connections. New research suggests men use (3) better than women.

Marie Lalanne and Paul Seabright of the Toulouse School of Economics (4) the effect of a network on (5) using a database of board members in Europe and America. They find that if you were to compare two executive directors, (6) in every way except that one had 200 ex-colleagues now (7) boards and the other 400, the latter, (8) , would be paid 6% more. For non-executives the gap is 14%.

The really (9) finding concerns the difference between the sexes. Among executive-board members, women earn 17% less than their male (10) . There are plenty of plausible explanations for this (11) , from interruptions to women’s careers to old-fashioned (12) . But the authors find that this pay gap can be fully (13) by the effect of executives’ networks. Men can leverage a large network into more senior positions or a seat on a more (14) board; women don’t seem to be able to.

Women could just have (15) connections with members of their networks. "Women seem more inclined to build and rely on only a few p relationships," says Mr. Seabright. Men are better at developing (16) acquaintances into a network, and better at maintaining a high personal (17) through these contacts. Women may, of course, also be hurt by the existing (18) of men on boards and a male (19) for filling executive positions with other men. But a tendency to think of other men first will be (20) if talented women don’t stay on the radar. (289 words)

6()

A.identical

B.similar

C.differential

D.distinctive