问题 选择题

NA代表阿伏加德罗常数,下列说法正确的是(  )

A.常温常压下,1mol水中含有NA个H+和NA个OH-

B.22.4LCO气体所含的分子数为NA

C.0.1mol/LBaCl2溶液中Cl-的数目是0.2NA

D.使56gFe2+还原为单质铁,需得到2NA个电子

答案

A、水是极弱的电解质,常温下水中电离出的氢离子和氢氧根离子浓度为10-7mol/mol,1L水中氢离子和氢氧根离子物质的量为10-7 mol,含有10-7NA个H+和NA个OH-,故A错误;

B、不是标准状况下,题中条件无法计算22.4L一氧化碳的物质的量,故B错误;

C、0.1mol/L BaCl2溶液的体积不知道,无法计算溶质的物质的量,故C错误;

D、56gFe2+的物质的量为1mol,完全变成单质铁得到2mol电子,得到2NA个电子,故D正确;

故选D.

单项选择题
阅读理解

The first and best of victories is for a man to conquer himself; to be conquered by himself is, of all things, the most shameful, says Plato. Self-control is at the root of all the advantages. Let a man give in to his impulses (冲动) and feelings, and from that moment he gives up his moral freedom.

A single angry word has lost many a friend. When Socrates found in himself any temper or anger, he would check it by speaking low in order to control himself. If you are conscious of being angry, keep your mouth shut so that you can hold back rising anger. Many a person has dropped dead in great anger. Fits of anger bring fits of disease. Whom the gods would destroy they first make mad. Keep cool, says George Herbert, for fierceness (狂怒) makes error a fault.

To be angry with a weak man is to prove that you are not strong yourself. Anger, says Pythagoras, brings with folly(愚蠢) and ends with regret. You must measure the strength of a man by the power of the feelings he conquers, not by the power of those which conquer him.

Self-control is man’s last greatest victory.

If a man lacks self-control he seems to lack everything. Without it he can have no patience, no power to govern himself; he can have no self-confidence, for he will always be controlled by his strongest feeling. If he lacks self-control, the very backbone and nerve of character are lacking also.

小题1: What does the reader learn from the first paragraph?

A.The greatest victory for a man is to conquer everything except himself.

B.One’s moral freedom is based on the control of himself.

C.To control oneself is the most difficult in one’s life.

D.If a person is too stubborn, he will feel most shameful.小题2: What is the correct interpretation of “Whom the gods would destroy they first make mad ”in paragraph 2 ?

A.If the gods want to kill you, they make you crazy first.

B.If you always lose your temper, you will soon be finished.

C.If you cannot control yourself, you will become crazy.

D.If you are mad, you will be punished by the gods.小题3: If a man lacks self-control, he lacks all of the following EXCEPT _______.

A.the very backbone and nerve of character

B.the patience and power to control himself

C.strong feelings

D.self-confidence小题4: The author’s main purpose in writing this article is to _______.

A.explain that self-control is the key to success

B.teach people how to control everything in order to make a great success

C.distinguish all kinds of self-control and suggest ways for keeping it

D.advise people not to lose temper so as to make and keep more friends小题5: The passage is mainly developed by _____.

A.analyzing causes

B.making comparisons

C.examining differences

D.listing quotations