题目

14.0 g铜银合金与足量某浓度的硝酸反应，将放出的气体与1.12 L(标准状况)氧气混合，通入水中恰好完全吸收，则合金中铜的质量为(    ) A.9.6 g                 B.6.4 g                  C.3.2 g                  D.1.6 g 答案：C 解析:由题意知，Cu、Ag与HNO3反应所得还原产物与O2作用溶于水后又变为HNO3，因此可以认为Cu、Ag所失电子最终被O2而非HNO3所得。 设Cu、Ag物质的量分别为x、y，则： 解得：x=0.050 mol， m(Cu)=64 g·mol－1×0.050 mol=3.2 gWhat exactly is a lie? Is it anything we say which we know is untrue? Or is it something more than that? For example, suppose a friend wants to borrow some money from you. You say, "I wish I could help you but I'm short of money myself." In fact you are not short of money but your friend is in the habit of not paying his debts and you don't want to hurt his feelings by reminding him of this. Is this really a lie?    Professor Gerald Gullion of the University of Southern California has made a scientific study of lying. According to him, women are better liars than men, particularly when telling a "white lie", such as a woman at a party telling another woman that she likes her dress when she really thinks it looks awful. However, this is only one side of the story. Other researchers say that men are more likely to tell more serious lies, such as making a promise which they have no intention of fulfilling. This is the kind of lie politicians and businessmen are supposed to be particularly skilled at: the lie from which the liars hopes to profit or gain in some way.Research has also been done into the changes of people’s behavior in a number of small, clearly unimportant ways when they lie. It has been found that if they are sitting down at the time, they tend to move about in their chairs more than usual. To the trained observer they are saying “I wish I were somewhere else now”. They also tend to touch certain parts of the face more often, in particular the nose. One explanation of this may be that lying causes a slight increase in blood pressure. The nose is very sensitive to such changes and the increased pressure makes it itch (痒).    Another gesture which gives away is what the writer Desmond Morris in his book Man Watching calls “the mouth cover”. He says there are several typical forms of this, such as covering part of the mouth with fingers, touching the upper-lip or putting a finger of the hand at one side of the mouth. Such a gesture can be understood, as an unconscious attempt on the part of the liar to stop himself or herself from lying. Of course, such gestures as rubbing the nose or covering the mouth, or moving about in a chair cannot be taken as proof that the speaker is lying. They simply tend to occur more frequently in this situation. It is not one gesture alone that gives the liar away but a whole number of things, and in particular the context in which the lie is told. 41. According to the passage, a “white lie” seems to be a lie _______.    A. that other people have interest in   B. that other people cannot believe   C. told in order to avoid offending(冒犯) someone   D. told in order to take advantage of someone42. Research suggests that women _______. A. are better at telling lies than men doB. generally lie far more than menC. often make promises they later breakD. lie at parties more often than men do 43. Researchers find that    when a person tells lies．A. his or her blood pressure increases greatlyB. he or she looks very serious and moves about moreC. he or she tends to make small changes in his behaviorD. he or she uses his unconscious mind44. One reason people sometimes rub their noses when they lie is that_______   A.1ying causes a slight increase in blood pressure   B. the nose is sensitive to physical changes caused by lying   C. they want to cover their mouths   D. they are trying to stop themselves from telling lies45. Which of the following may best betray (出卖) a liar?   A. The touching of the tip of one’s nose．   B. The change of one’s behavior.    C. “The mouth cover” gesture.    D. The situations in which his lies are told．