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问题 选择题

下表是25°C时某些盐的浓度积常数和弱酸的电离平衡常数，下列说法正确的是（　　）

化学式AgClAg2CrO4CH3COOHHClOH2CO3
Ksp或KaKsp=1.8×10-10Ksp=2.0×10-12Ka=1.8×10-5Ka=3.0×10-8Ka1=4.1×10-7

Ka2=5.6×10-11

A．相同浓度CH3COONa和NaClO的混合液中，各离子浓度的大小关系是c（Na+）＞c（ClO-）＞c（CH3COO-）＞c（OH-）＞c（H+）

B．碳酸钠溶液中滴加少量氯水的离子方程式为CO32-+Cl2+H2O═HCO3-+Cl-+HClO

C．向0.1mol•L-1 CH3COOH溶液中滴加NaOH溶液至c（CH3COOH）：c（CH3COO-）=5：9，此时溶液pH=5

D．向浓度均为1×10-3mol•L-1的KCl和K2CrO4混合液中滴加1×10-3mol•L-1的AgNO3溶液，CrO42-先形成沉淀

答案

A．次氯酸根离子的水解程度大于醋酸根离子，所以c（CH3COO-）＞c（ClO-），故A错误；

B．HClO的电离平衡常数大于HCO3-，所以次氯酸的酸性大于碳酸氢根离子，则碳酸钠和少量氯水反应的离子方程式为：CO32-+Cl2+H2O═HCO3-+Cl-+H++ClO-，故B错误；

C．缓冲溶液中pH=pKa+lg

[弱酸盐]
[弱酸]
=4.8+lg
9
5
=5.055≈5，故C正确；

D．混合溶液中生成氯化银需要的c（Ag+）=

Ksp(AgCl)
c(Cl-)
=
1.8×10-10
1×10-3
mol/L=1.8×10-7mol/L，生成Ag2CrO4需要的c（Ag+）=
Ksp
c(CrO42-)
=
2.0×10-12
1×10-3
mol/L=4.47×10-5mol/L，所以氯化银先沉淀，故D错误；

故选C．

阅读理解

It is true that people with better education are usually able to get better paying jobs. In other words, they have more chances to choose a good job while people with little or no education don’t. It seems that the purpose of education is to make people get jobs. But this isn’t accepted by all people.

Some people may think that a person should spend the best years of his life to get education only for a way of living. This was probably one of the earliest reasons of education. In fact, if education is just a way of making a living, people don’t need to spend so much time in school. People can get education for a living in a short time. Subjects like history and geography need not be taught to everyone. Even language and mathematics need not be taught in detail(详细地), either. Here it is clear that education is much more than teaching a man to get a way of living.

Education is well-rounded and it is mainly for improving a man. It is not only to teach him to speak, read and write, but also to develop his creative thinking and other abilities. After that, it is to make him a wise man and thankfully enjoy the achievements of human. Education is to make a man lead a better life. Educated people are expected to be able to listen to good music, read good books, watch plays and most of them take an interest in the world.

I would agree that making a good living is an important reason for education, but certainly not the most important or the main reason.

小题1:People with little education usually ____.

A．spend a long time in school

B．have a good chance to get a job

C．spend the best years to choose jobs

D．have fewer chances to get a good job小题2:The earliest education was probably to ______.

A．make a man lead a better life

B．teach a man to write and think

C．make people get a way of living

D．teach people to read good books小题3:It is expected that educated people will be able to _____.

A．accept education as a way of living

B．take an interest in the whole world

C．develop their abilities to make plays

D．learn subjects like language and math
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单项选择题

阅读下文，回答下列各题。

。约言之，藏书的当能铸冶治学的风气，影响学风，学术思想的活跃，学术思想的活跃又进一步学风，并给著述提供津梁。战国时期学术的百家争鸣的出现，无疑与图书事业的发展有千丝万缕的联系。

。梁代萧绎出任荆州称帝江陵，，招致饱学之士如林，使长江中游地方出现了一次学风高潮，成为全国性的文化中心。明末士大夫藏书已成风气，这把许多士人学子引向了读书治学，蔚然而兴学风。明清学风在江南大盛，而江南藏书号称最富，全国性的藏书胜所大约在燕京、金陵、姑苏、临安四地，而江南奄有三处。虞山人钱谦益降云楼藏书几可与内府相埒(liè等同)。郑人范钦天一阁藏书为两浙第一。常熟人毛晋藏书达84000册之巨。《清代藏书楼发展史》一书说，明清的藏书事业如火炬一样被传递着”，“使它成为此后三百年中推动学术发展的一个重要力量”。藏书之所往往是人文荟萃之地。江南多藏书，故江南多才士，已为世所称道。藏书之所往往是人文荟萃的地方。前说南梁江陵曾为一个文化中心，有藏书十余万卷，文人学士多会于斯。公元544年西魏大军攻破江陵，十余万卷图书付之一炬，藏书毁灭殆尽，这个学术中心便不复存在，使斯地出现过好几百年的人文萧条。

文中处被抽取出来的一项内容应该是（）。

A．《庄子·天下》曰：“惠施多方，其书五年。”

B．《论语·季氏》曰：“不学诗无以言!”

C．《庄子·养生主》曰：“吾生也有涯，而知也无涯。”

D．《论语·学而》曰：“学而时习之，不亦说乎”
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