问题 填空题

(3分)以黄铜矿(主要成分是CuFeS2,含少量杂质SiO2)为原料炼铜的方法分为高温炼铜和湿法炼铜两种。近年来,湿法炼铜有了新进展,科学家发现有一种细菌在酸性水溶液、氧气存在下,可以将黄铜矿氧化成硫酸盐,某工厂运用该原理生产铜和绿矾(FeSO4的晶体,含结晶水)。

回答下列问题:

(1)写出反应Ⅰ的化学反应方程式:                           

(2)欲从溶液中获得绿矾晶体,分离“操作2”应为蒸发浓缩、       过滤。

答案

(1)4CuFeS2+17O2+2H2SO4== ==2Fe2(SO4)3+4CuSO4+2H2O (少条件、不配平共扣1分,化学式错、少物质该空为0分)(2)降温结晶

根据反应物、生成物和反应条件,依据质量守恒定律和化学方程式的书写方法,可以写出正确的化学方程式.

单项选择题

The "standard of living" of any country means the average person’s share of the goods and services which the country produces. A country’s standard of living, (1) , depends first and (2) on its capacity to produce wealth." Wealth" in this sense is not money, for we do not live on money (3) on things that money can buy. "Goods" such as food and clothing, and "services" such as transport and " (4) ". A country’s capacity to produce wealth depends upon many factors, most of (5) have an effect on one another. Wealth depends (6) a great extent upon a country’s natural resources. Some regions of the world are well supplied with coal and minerals, and have a fertile soil and a (7) climate; other regions possess none of them.

Next to natural resources (8) the ability to turn them to use. China is perhaps as well (9) as the USA in natural resources, but suffered for many years from civil and (10) wars, and (11) this and other reasons was (12) to develop her resources. (13) and stable political conditions, and (14) from foreign invasion, enable a country to develop its natural resources peacefully and steadily, and to produce more wealth than another country equally well (15) by nature but less well ordered.

A country’s standard of living does not only depend upon the wealth that is produced and consumed (16) its own borders, but also upon what is indirectly produced through international trade. (17) , Britain’s wealth in foodstuffs and other agricultural products would be much less if she had to depend only on (18) grown at home. Trade makes it possible for her surplus manufactured goods to be traded abroad for the agricultural products that would (19) be lacking. A country’s wealth is, therefore, much influenced by its manufacturing capacity, (20) that other countries can be found ready to accept its manufactures.

4()

A.recreation

B.enlightenment

C.refreshment

D.entertainment

问答题