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问题 选择题

已知：Ksp（Ag2SO4）=1.4×10-5，Ksp（BaSO4）=1.1×10-10，Ksp（CaSO4）=9.1×10-6，Ksp（BaCO3）=2.6×10-9．则下列说法中不正确的是（　　）

A．有关的四种盐中溶解性最强的是Ag2SO4

B．有关的三种硫酸盐中，其饱和溶液中硫酸根离子浓度最小的是BaSO4

C．CaSO4沉淀能较容易地转化成为BaSO4沉淀

D．BaSO4沉淀不可能会转化成BaCO3沉淀

答案

A、Ag2SO4的溶度积常数最大，一般来说，难溶电解质的溶度积常数越大，物质的溶解性越强，故A正确；

B、Ag2SO4饱和溶液中硫酸根离子浓度为

3
1.4×10-5
2
，BaSO4饱和溶液中硫酸根离子浓度为
1.1×10-10
，

CaSO4饱和溶液中硫酸根离子浓度为

9.1×10-6
，三种硫酸盐中，其饱和溶液中硫酸根离子浓度最小的是BaSO4，故B正确；

C、BaSO4的溶度积常数小于CaSO4，则CaSO4沉淀能较容易地转化成为BaSO4沉淀，故C正确；

D、当溶液中c（Ba2+）×c（CO32-）＞9.1×10-6时，可实现BaSO4沉淀转化成BaCO3沉淀，故D错误．

故选D．

单项选择题

Cooperation is the common endeavor of two or more people to perform a task or reach a jointly cherished goal. Like competition and conflict, there are different forms of cooperation, based on group organization and attitudes.In the first form, known as primary cooperation, group and individual unite. The group contains nearly all of each individual’’s life. The rewards of the group’’s work are shared with each member. There is an interlocking identity of individual, group, and task performed. Means and goals become one, for cooperation itself is valued.While primary cooperation is most often characteristic of preliterate societies, secondary cooperation is characteristic of many modern societies. In secondary cooperation, individuals devote only part of their lives to the group. Cooperation itself is not a value. Most members of the group feel loyalty, but the welfare of the group is not the first consideration. Members perform tasks so that they can separately enjoy the fruits of their cooperation in the form of salary, prestige, or power. Business offices and professional athletic teams are examples of secondary cooperation.In the third type, called tertiary cooperation or accommodation, latent conflict underlies the shared work. The attitudes of the cooperating parties are purely opportunistic; the organization is loose and fragile. Accommodation involves common means to achieve antagonistic goals; it breaks down when the common means cease to aid each party in reaching its goals. This is not, strictly speaking, cooperation at all, and hence the somewhat contradictory term antagonistic cooperation is sometimes used for this relationship.

The word "fragile" in the last paragraph is closest in meaning to________.

A．inefficient

B．easily broken

C．poorly planned

D．involuntary
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多项选择题

（）建立信息共享机制，监管人民币境外直接投资业务活动。

A.中国人民银行

B.国家外汇管理局

C.境外直接投资主管部门

D.工商管理局
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