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问题 填空题

铬铁矿的主要成分的化学式为FeO·Cr2O3，还含有SiO2、Al2O3等杂质。工业上常采用固体碱熔氧化法用铬铁矿粉制备重铬酸钾，流程为：

已知：①NaFeO2遇水强烈水解；

②重铬酸钾为橙红色针状晶体，溶于水，不溶于乙醇，有强氧化性；

③2CrO42－ + 2H+Cr2O72－+ H2O

（1）灼烧操作一般在坩埚中进行，下列物质适合用来制作此实验坩埚材料的是      

A．铁

B．氧化铝

C．石英

D．陶瓷（2）①铬铁矿经粉碎处理的目的是                                            。

②写出Cr2O3和纯碱、氧气反应生成Na2CrO4的化学方程式为                ；

③NaFeO2水浸时强烈水解生成氢氧化铁沉淀，离子方程式为___           ___。

（3）滤液1的成分除Na2CrO4、NaOH外，还含有（填化学式）            ，

（4）通过途径Ⅰ从Na2CrO4溶液获得K2Cr2O7晶体，操作步骤有：“酸化”→加KCl固体→蒸发浓缩→操作a→过滤→洗涤→干燥。

① “酸化”步骤用醋酸调节溶液pH＜5，其目的是                 ；

②操作a的名称                            。

答案

（1）A ( 3分）

（2）① 增大反应物的表面积，加快反应速率（2分）

② 2Cr2O3 + 3O2+4Na2CO3 4Na2CrO4+4CO2↑（3分，未配平扣1分）

③ FeO2－+2H2O=Fe(OH)3↓+OH－ （3分，未配平扣1分）

（3）NaAlO2 、Na2SiO3（2分）

（4）①使2CrO42－ + 2H+Cr2O72－+ H2O 的平衡向正反应方向移动，尽量将CrO42-转化为Cr2O72-（2分）

②冷却结晶（1分，只写冷却或只写结晶不得分）

题目分析：（1）陶瓷中含二氧化硅，石英的作用成分是二氧化硅，氢氧化钠与氧化铝、二氧化硅反应，所以适合用来制作此实验坩埚材料的是铁，答案选A；

（2）①粉碎固体使其与反应物的接触面积增大，加快反应速率；

② 根据元素守恒判断Cr2O3和纯碱、氧气反应生成Na2CrO4和二氧化碳，化学方程式为

2Cr2O3 + 3O2+4Na2CO3 4Na2CrO4+4CO2↑；

③ NaFeO2水浸时强烈水解生成氢氧化铁沉淀，书写离子方程式时可逆符号变为“=”，离子方程式为

FeO2－+2H2O=Fe(OH)3↓+OH－

（3）SiO2、Al2O3等杂质与氢氧化钠反应生成硅酸钠、偏铝酸钠，所以滤液1的成分除Na2CrO4、NaOH外，还含有NaAlO2 、Na2SiO3

（4）①根据已知③Na2CrO4溶液中存在2CrO42－ + 2H+Cr2O72－+ H2O平衡，加入醋酸调节pH<5，使平衡正向移动，尽量将CrO42-转化为Cr2O72-

②由溶液得到晶体的一般步骤是加热浓缩、冷却结晶、过滤、洗涤、干燥，所以本实验中加热浓缩后应冷却结晶。

选择题

“……帝国鉴于内外的形势，认为帝国当前应该确立的根本国策，在于外交和国防相互配合，一方面确保帝国在东亚大陆的地位，另一方面向南方海洋发展。”下列哪些属于 “帝国”当时所处的“内外的形势”

①帝国建立了军事法西斯专政 ②帝国军队深陷于中国战场 

③德军基本征服西欧          ④德国一再践踏《凡尔赛和约》 

⑤美国国会通过了《中立法》

A．①②③

B．①②③④

C．①③④

D．①④⑤
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单项选择题

Despite much loose talk about the new global economy, today’s international economic integration is not unprecedented. The 50 years before the first world war saw large cross-border flows of goods, capital and people. That period of globalization, like the present one, was driven by reductions in trade barriers and by sharp falls in transport costs, thanks to the development of railways and steamships. The present surge of globalization is in a way, a resumption (恢复) of that previous trend. The earlier attempt at globalization ended abruptly with the first world war. after which the world moved into a period of fierce trade protectionism and tight restrictions on capital movement. During the early 1930s, America sharply increased its. tariffs, and other countries retaliated (报复), making the Great Depression even greater. The volume of world trade fell sharply. International capital flows virtually dried up in the interwar period as governments imposed controls to try to insulate (隔离) their economies from the impact of a global slump.

Capital controls were maintained after the second world war, as the victors decided to keep their exchange rates fixed on arrangement known as the Bretton Woods System, named after the American town in which it was approved. But the big economic powers also agreed that reducing trade barriers was vital to recovery. They set up the General Agreement on Tariffs and Trade (GATT), which organized a series of negotiations that gradually reduced import tariffs. GATT was replaced by the World Trade Organization (WTO) in 1995. Trade flourished.

In the early 1970s, the Bretton Woods System collapsed and currencies were allowed to float against one another at whatever rates the markets set. This signaled the rebirth of global capital market. America and Germany quickly stopped trying to control the inflow and outflow of capital, Britain abolished capital controls in 1979 and Japan (mostly) in 1980. This is part of the reason why continental Europeans tend to worry more about the power of global capital markets. America has been exposed to them for much longer.

Two forces have been driving these increased flows of goods and money. The first is technology. With the costs of communication and computing falling rapidly, the natural barriers of time and space that separate national markets have been falling too. The second driving force has been liberalization. As a result of both the GATT negotiations and unilateral (单方面的，单边的) decisions, almost all countries have lowered barriers to foreign trade. Most countries have welcomed international capital as well.

World trade flourished after WWⅡ due to （）。

A. capital controls

B. fixed exchange rates

C. reduction in trade barriers

D. establishment of WTO
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