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问题 填空题

（1）现有标准状况下的氮气5.6g，其体积为______L，含有氮分子的数目为______．

（2）写出电解食盐水的化学方程式：______；

写出实验室制取氯气的化学方程式：______．

答案

（1）V=n×Vm=

m
M
×Vm=
5.6g
28g/mol
×22.4L/mol=4.48L；

N=n×NA=

m
M
×NA=
5.6g
28g/mol
NA=0.2NA

故答案为：4.48L；0.2NA

（2）电解饱和食盐水的反应物是氯化钠和水，产物是氢氧化钠和氯气、氢气，反应条件是电解，故答案为：2 NaCl+2H2O

 电解 
.
 
2NaOH+Cl2↑+H2↑

实验室制取氯气的反应物是二氧化锰和浓盐酸，产物是氯化锰和氯气、水，条件是加热，该反应中二氧化锰作氧化剂，浓盐酸是还原剂，

故答案为：MnO2+4HCl（浓）

 加热 
.
 
MnCl2+Cl2↑+2H2O

完形填空

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1. A. eight years old          B. eight year old 

C. eight-year-old           D. eight-years-old

2. A. by        B. on        C. from         D. in

3. A. so         B. but       C. while         D. because

4. A. hard                    B. late           C. happy             D. easy

5. A. Each                    B. Both                   C. None                       D. Some

6. A. walk                    B. run            C. drive                        D. ride

7. A. strange     B. busy                   C. strong            D. poor

8. A. feels                    B. keeps                 C. sees                         D. likes

9. A. tell             B. know                  C. visit                          D. ask

10. A. so many     B. so much     C. too much   D. many too
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单项选择题

以下四个数中，最小的数是（）。

A.32

B.36H

C.22H

D.10101100B
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