问题 选择题

以海水中常见物质NaCl为原料可以发展很多种工业,

(1)写出电解饱和食盐水的化学方程式______________________。

(2)以氯碱工业中的某些物质为原料制取漂白粉的化学方程式是_______________________

(3)从海水中获取的食盐中通常含有少量的MgCl2、Na2SO4等杂质,现采取下列方案将其提纯,其合理的操作顺序是________________________________

①取一定量的食盐晶体溶于水 ②加入过量的NaOH溶液 ③加入过量的BaCl2溶液 

④过滤  ⑤蒸发溶液  ⑥加入过量的Na2CO3溶液 ⑦加入适量的盐酸,调节溶液的pH

Ⅱ:2007年11月18日凌晨乌克兰一煤矿因瓦斯爆炸而发生矿难,死亡人数超过100人;2007年12月12日,河南省某煤矿因发生煤矿瓦斯突发事故而导致12名矿工遇难.瓦斯是CH4和CO混合而成的有毒气体,遇到明火极易发生爆炸

(4)等体积的CO和CH4在相同条件下分别完全燃烧,转移的电子数之比     

(5)已知在101kPa时,CO的燃烧热为283kJ/mol,相同条件下若2molCH4完全燃烧生成液态水,所放出的热量为1molCO完全燃烧放出热量的6.3倍,写出CH4完全燃烧的热化学方程式

                                                            

120℃,101kPa下,a ml由CO、CH4组成的混合气体在bmlO2中完全燃烧后,恢复到原温度和压强

(6)若混合气体和O2恰好完全反应,产生bmlCO2,则混合气体中CH4的体积分数为    

(7)若燃烧后气体体积缩小了a/4ml,写出a与b必须满足的关系式                  

答案

Ⅱ:(4),转移的电子数之比1:4

(5)CH4(g)+2O2(g)=CO2(g)+2H2O(l)  △H="-891.45kJ/mol"  

(6) CH4的体积分数为 33.3%

(7) a与b必须满足的关系式 4b5a

(1)电解饱和食盐水:

(2)制取漂白粉的原理是利用:氯气与碱反应生成盐、次氯酸盐、水。生成的次氯酸盐具有强氧化性,可用于漂白。其方程式:

(3)除去食盐中含有少量的MgCl2、Na2SO4等杂质所需试剂:NaOH、BaCL2、Na2CO3、HCL,加入试剂必须符合:BaCL2放在Na2CO3之前,HCL一定放在最后的原则。

(4)等体积的CO和CH4在相同条件下的物质的量之比为1:1,可令其物质的量分别为1mol,CO中C元素化合价将由+2价升高到+4价,转移电子数为2mol;CH4中C元素化合价将由-4价升高到+4价,转移电子数为8mol;

(5)CH4(g)+2O2(g)=CO2(g)+2H2O(l)  △H=-891.45kJ/mol

(6)设CO有(a-x)mL,CH4有x mL;则

根据C守恒得:a="b" ①;;解得

(7)对于反应2CO+O2====(点燃)2CO2为气体体积减小的反应,对于反应CH4+2O2====(点燃)CO2+2H2O120℃,101kPa下,为等体积反应;由方程式

2CO+O2====(点燃)2CO2气体体积减小△V

2    1      2           1

                 

CH4+2O2====(点燃)CO2+2H2O

   a        a

,得4b≥5a

完形填空
完形填空。

                                                              Joy in the Journey
     If you have ever been discouraged because of failure, please read on. For often, achieving what you
set out to do is not the important thing. Let me   1   .
     Two brothers decided to  2   a deep hole behind their house. As they were working, a couple of older boys stopped by to   3   .
     "What are you doing?" asked one of the visitors.
     "We plan to dig a hole all the way through the  4   !" one of the brothers volunteered   5   .
     The older boys began to  6  , telling the younger ones that digging a hole all the way through the earth
was  7   . After a long silence, one of the   8    picked up a jar full of spiders,   9   and many other kinds
of insects. He   10   the lid and showed the wonderful   11  to the scoffing (嘲笑的) visitors. Then he
said quietly and confidently, "Even if we don't dig all the way through the earth, look at what we have
found   12   the way!"
     Their goal was far too ambitious, but it did cause them to dig. And that is    13  a goal is for - to cause
us to move in the direction we have chosen,   14   , to set us digging!
     But not every goal will be fully   15   . Not every job will end   16  . Not every hope will come to pass. Not every love will last. Not every dream will be   17   . But when you fall short of your aim, perhaps you can say, "Yes,   18    look at what I've found along the way! Look at the wonderful things   19  my life
because I tried to do something!" It is in the digging that life is lived. And I believe it is the joy in the
journey, in the end, that truly  20   .

( )1. A. say    
( )2. A. find    
( )3. A. rest    
( )4. A. house  
( )5. A. calmly    
( )6. A. laugh  
( )7. A. important
( )8. A. passers-by
( )9. A. worms    
( )10. A. moved    
( )11. A. contents
( )12. A. in  
( )13. A. what  
( )14. A. other than
( )15. A. made  
( )16. A. hopelessly
( )17. A. come true
( )18. A. and    
( )19. A. breaking into
( )20. A. matters  
B. explain  
B. fill   
B. work  
B. earth  
B. patiently  
B. think  
B. difficult
B. watchers
B. rabbits  
B. removed  
B. scenes  
B. along  
B. how    
B. in other words
B. prepared
B. pleasantly
B. realized
B. or    
B. turning to
B. happens               
C. think
C. dig  
C. laugh
C. wall  
C. excitedly
C. stare
C. impossible
C. visitors
C. wolves  
C. broke
C. pictures
C. to    
C. where  
C. rather than
C. produced
C. surprisingly
C. made  
C. but  
C. coming into  
C. appears
D. study          
D. search          
D. watch          
D. road            
D. impatiently    
D. smile          
D. interesting    
D. diggers        
D. flies          
D. pushed          
D. jars            
D. out            
D. which          
D. instead        
D. achieved        
D. successfully    
D. predicted      
D. so              
D. holding to   
D. proves        
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