问题 问答题 简答题

试述几种常见的无机化学反应。

答案

参考答案:

(1)化合反应:由两种或两种以上的物质生成另一种物质的反应,叫化合反应。例如:2Mg+O2=2MgO

(2)分解反应:由一种物质生成两种或两种以上其它物质的反应,叫分解反应。例如:

2NaHCO3=Na2CO3+H2O+CO2

(3)置换反应:一种单质和一种化合物起反应,生成另一种单质和另一种化合物的反应叫做置换反应。一般包括两种:

a、置换出金属或氢气:

Fe+CuSO4=FeSO4+Cu

Zn+H2SO4(稀)=ZnSO4+H2

b、置换出非金属:

2NaBr+CL2=2NaCl十Br2

2HI+Br2=2HBr+I2

(4)复分解反应:两种电解质相互交换离子,生成两种新的电解质的反应;

复分解反应能否发生,要看生成物中是否生成难溶物。气体或难电离的物质。此外,也要看参加反应的两种化合物的性质(溶解性及酸性强弱等)。例如NaCl和Cu(OH)2就不发生反应,因为Cu(OH)2不溶于水。

中和反应属于复分解反应,专指酸和碱作用生成盐和水的反应。

单项选择题
单项选择题

When something goes wrong, it can be very satisfying to say," Well, it’s so-and-so’s fault. "or "I know I’m late, but it’s not my fault ; the car broke down. "It is probably not your fault, but once you form the habit of blaming somebody or something else for a bad situation, you are a loser. You have no power and could do nothing that helps change the situation. However, you can have great power over what happens to you if you stop focusing on whom to blame and start focusing on how to remedy the situation. This is the winner’s key to success.

Winners are great at overcoming problems. For example, if you were late because your car broke down, maybe you need to have your car examined more regularly. Or, you might start to carry along with you the useful phone numbers, so you could call for help when in need. For another ex-ample, if your colleague causes you problems on the job for lack of responsibility or ability, find ways of dealing with his irresponsibility or inability rather than simply blame the person. Ask to work with a different person, or don’t rely on the person. You should accept that the person. Ask to work with a different person, or don’t rely on this person. You should accept that the person is not reliable and find creative ways to work successfully regardless of how your colleague fails to do his job well.

This is what being a winner is all about—creatively using your skills and talents so that you are successful no matter what happens. Winners don’t have fewer problems in their lives ; they have just as many difficult situations to face as anybody else. They are just better at seeing those problems as challenges and opportunities to develop their own talents. So, stop focusing on "whose fault it is". Once you are confident about your power over bad situations, problems are just stepping stones for success.

According to the passage, winners () .

A. deal with problems rather than blame others

B. meet with fewer difficulties in their lives

C. have responsible and able colleagues

D. blame themselves rather than others