问题 填空题

下列离子方程式中正确的是______________

(1)氢氧化亚铁溶于稀硝酸中:Fe(OH)2 + 2H+ = Fe2+ + 2H2O

(2)过量的NaHSO4与Ba(OH)2溶液反应:  Ba2+2OH+2H+SO42= BaSO4↓+2H2O

(3)向Ba(OH)2溶液中滴加NH4HSO4溶液至刚好沉淀完全:

Ba2++2OH+NH4++H++SO42=BaSO4↓+NH3·H2O+ H2O

(4)过量氯气通入溴化亚铁溶液中3C12 +2Fe2++4Br=6C1+2Fe3++2Br2

(5)H218O中投入Na2O2固体:2H218O+2O22-=4OH-18O2

(6)NH4HCO3溶液中加足量NaAlO2溶液:NH4++AlO2+2H2O= NH3·H2O+ Al(OH)3

(7)0.1mol/L CuCl2溶液中加入0.1mol/L NaHS溶液:Cu2++2HS-+2H2O=Cu(OH)2↓+2H2S

(8)等物质的量的KHCO3和Ba(OH)2的溶液混合:HCO3+Ba2++OH= BaCO3↓+H2O

(9)向明矾溶液中逐滴加入Ba(OH)2溶液至Al3+刚好沉淀完全:

Al3+ +SO42—+Ba2+ +3OH==BaSO4↓+Al(OH)3

(10)NaHCO3溶液水解:HCO3+ H2O  CO32+ H3O+

(11)硫化钠水溶液呈碱性的原因:S2-+2H2O  H2S↑+2OH

(12)在碳酸氢镁溶液中加入足量Ca(OH)2溶液:

Mg2++HCO3+Ca2++2OH="=" MgCO3↓+CaCO3↓+2H2O

(13)用石墨作电极电解AlCl3溶液:2Cl+2H2O  Cl2↑+H2↑+2OH

(14)向饱和碳酸钠溶液通入过量的二氧化碳气体:CO32-+CO2+H2O=2HCO3

答案

(2)、(3)、(4)、(8)

完形填空
完形填空。
     People are often killed when they __1___ the road. Most of these people are old people and
 children. Old people are often killed because they can not see __2___ hear very well. Children are often
 killed because they are not __3___. They forget to look and listen before they cross the road.     
     A car, truck or bus cannot stop very ___4__. If the car-is going very fast, it will travel __5___ 
 meters  before it stops. People don't always understand this. They think a car can stop __6___ a few
  meters. The  faster a car __7___, the longer it takes to ___8__. It is very difficult for a person to know
 how fast a car is traveling.    
     The ___9__safe way to cross the road is to look in both directions, right and left. Then ___10__ the
 road is clear, it is safe to cross. The right way to cross the road ___11__to walk quickly. It is not
__12___ to run across the road. If people run across the road, they may fall __13___.
( ) 1.A.over
( ) 2.A.and  
( ) 3.A.care
( ) 4.A.shortly
( ) 5.A.much
( ) 6.A.during
( ) 7.A.traveling
( ) 8.A.fly  
( ) 9.A.few  
( ) 10.A.if
( ) 11.A.is
( ) 12.A.hard
( ) 13.A.down
B.across  
B.but    
B.careful  
B.early    
B.more    
B.among    
B.is traveling
B.go    
B.only  
B.before  
B.has    
B.danger  
B.to    
C.cross
C.both
C.strong
C.quickly
C.many
C.between
C.travel
C.stop
C.often
C.which
C.are
C.safe
C.up
D.through      
D.or          
D.healthy      
D.slowly      
D.a lot        
D.in          
D.is to travel
D.move        
D.always      
D.what        
D.have        
D.dangerous    
D.under        
单项选择题