问题 问答题

观察法:先金属后原子团

(1)CuSO4+NaOH═Na2SO4+Cu(OH)2

(2)Mg+HCl═MgCl2+H2

(3)Fe2O3+H2SO4═Fe2(SO43+H2O

(4)Al+H2SO4═Al2(SO43+H2

(5)Fe(OH)3+H2SO4═Fe2(SO43+H2O

(6)Al2(SO43+NaOH═Na2SO4+Al(OH)3

答案

配平化学方程式关键是保证等号两边各原子的数目相等,用最小公倍数法再结合观察法即可一一配平(观察法:先金属后原子团)

(1)本题可利用“定一法”进行配平,把Cu(OH)2的化学计量数定为1,则CuSO4、NaOH、Na2SO4前面的化学计量数分别为:1、2、1,故化学方程式为CuSO4+2NaOH═Na2SO4+Cu(OH)2;.

(2)利用观察法,则可配平化学方程式,Mg+2HCl═MgCl2+H2↑.

(3)此为复分解反应,利用其特点“内项结合,外项结合”,结合化合价书写化学式,利用观察法书写配平化学方程式Fe2O3+3H2SO4═Fe2(SO43+3H2O,;

(4)2Al+3H2SO4═Al2(SO43+3H2↑;等号前1个SO42-,一个Al,等号后有3个SO42-,2个Al,所以在Al 前配2,在H2SO4前配3,再观察可知H2前配3即可,故答案为:2Al+3H2SO4=Al2(SO4)+3H2

(5)此为复分解反应,利用其特点“内项结合,外项结合”,结合化合价书写化学式,利用观察法书写配平化学方程式2Fe(OH)3+3H2SO4═Fe2(SO43+6H2O,;

(6)此为复分解反应,利用其特点“内项结合,外项结合”,结合化合价书写化学式,利用观察法书写配平化学方程式Al2(SO43+6NaOH═3Na2SO4+2Al(OH)3

故答案为:

(1)CuSO4+2NaOH═Na2SO4+Cu(OH)2;(2)Mg+2HCl═MgCl2+H2↑,

(3)Fe2O3+3H2SO4═Fe2(SO43+3H2O;(4)2Al+3H2SO4═Al2(SO43+3H2↑;

(5)2Fe(OH)3+3H2SO4═Fe2(SO43+6H2O;

(6)Al2(SO43+6NaOH═3Na2SO4+2Al(OH)3

单项选择题 A1/A2型题
阅读理解

第三部分:阅读理解(共20小题; 每小题2分, 满分40分)

Everyone likes to feel that he or she is special.

Unfortunately, many of us grow up believing that we’re not special at all. We wish that we could be better at sports or more attractive. We wish we had nicer clothes or more money. Like the Scarecrow, the Tin Man, or the Cowardly Lion from The Wizard of Oz (《绿野仙踪》), we believe we’re not good enough just as we are. In the movie, the Scarecrow wishes that he had a brain. The Tin Man wishes he had a heart, and the Lion wants courage. In the end, each of them realizes that he already has what he needs.

Most parents want us to be the best we can be. They sometimes try to encourage us to do better by comparing us to others. They mean well, but the message we often get is that we’re not good enough. We begin to believe that the only way we can be special is by being better than someone else, but we are often disappointed. There will always be someone out there who is better than we are at something. There are plenty of people around who may not be as smart as we are but who are better at sports. Or they may not be as good-looking, but they have more money. It is impossible for us to be better than everyone else all the time.

Like the Scarecrow, the Tin Man, and the Cowardly Lion, we all want what we believe will make us better people. What we don’t realize is that often we already have inside us the very things that we seek. Parents sometimes forget to tell us that we are special, that we are good enough just as we are. Maybe no one told them that when they were growing up, or maybe they just forgot. Either way, it’s up to us to remind them from time to time that each of us, in our own way, is special. What we are ... is enough.

56. This passage is most likely written by a ______.

A. teenager     B. parent C. teacher       D. coach

57. According to the author, it seems improper for parents to ______.

A. compare their children with others now and then

B. give no pressure to their children 

C. remind their children frequently they are special

D. praise their children too much

58. By discussing the characters in The Wizard of Oz, the author mainly wants to show ______.

A. we are not good enough just as we are

B. we already have inside us what we want

C. it is impossible for us to be better than others

D. there is always someone who is better than us

59. What does the author of this passage believe?

A. Not everyone can be special.                 

B. Smart people are more special than others.

C. The richer you are, the better you are.           

D. We are all good enough just the way we are.