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5.(11分)电解原理在化学工业中有广泛应用。右图表示一个电解池,

装有电解液a;X、Y是两块电极板,通过导线与直流电源相连。

请回答以下问题:

(1)若X、Y都是惰性电极,a是饱和NaCl溶液,实验开始时,同

时在两边各滴入几滴酚酞试液,则

①电解池中X极上的电极反应式为                    

在X极附近观察到的现象是                       。 

②Y电极上的电极反应式为                        

检验该电极反应产物的方法是                        

(2)如要用电解方法精炼粗铜,电解液a选用CuSO4溶液,则

  ①X电极的材料是      ,电极反应式是               

  ②Y电极的材料是       ,电极反应式是              

 (说明:杂质发生的电极反应不必写出)

(3)工业品氢氧化钾的溶液中含有某些含氧酸杂质,可用离子交换膜法电解提纯。 电解槽内装有阳离子交换膜(只允许阳离子通过),其工作原理如图所示.              ①该电解槽的阳极反应式是____________________________. ②通电开始后,阴极附近溶液pH会增大,请简述原因               

_____________________________________________________________________________________________________________________________________________. ③除去杂质后的氢氧化钾溶液从溶液出口_________________(填写“A”或“B”)导出

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第三节 书面表达 (满分25分)假若你叫李华,在2008年5月12日发生的汶川地震中,家园被毁,学校坍塌,你遭受了巨大的精神创伤。几个月过去了,你的美国笔友David十分关心你的状况,来信询问。请你写一封120-150词的电子邮件,感谢他的关心,并告诉他,中国政府以及全国人民都在帮助你们重建家园,自己也会鼓起勇气,树立信心,为重建一个更加美好的家乡做出自己的贡献。

Dear David,

                                                                          

                                       

                                       

                                        

                                       

                                       

                                        

                                       

                                       

                                       

                                        

                                                                          

                                         

                                       

                                       

                                                      Yours,

                                   Li Hua      

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第一节   单词填空(共10小题,每小题0.5分,满分5分)

1.The teacher advised him to build his ____________ (词汇量) by doing more reading.

2.Everything needs to be done according to a certain _______________(原则,原理)

3.Two-thirds of the people died or were     (受伤)during the earthquake

4.If you are discovered smoking in the stadium, you will be __________(罚款).

5. We all ___________(钦佩)her for the way she saved the children from the fire.

6. After three hours of waiting for the train, our p____________ finally went to end.

7. We’d better take time and money into c_____________ when making the plan.

8. China achieved brilliant a___________ achievements in the 2004 Athens Olympic Games.

9. Despite his l     of experience, the young man finally got the job because of his creativity.

10. The thief a___________ to enter the house through the open window but he failed. 

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