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
N
A
=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

I like my bike. It brings me a lot of fun. When I was an  1  boy, my father bought it for me. It is my “horse”. I often go to school  2   my bike. I like riding a bike  3  it is very convenient. If I go out by bike, it is  4  to find a place for parking it. Bikes are very cheap, so most people can buy one. There are three people in my family.  5  of us has a bike. My parents are teachers in my school. In the morning, Mum, Dad and I each  6  to school. However on a rainy day we walk to school, because the road is bad for riding. I think riding bikes can make us  7  . It not only helps us exercise more but also  8  the air clean. The bike is very important in Chinese people’s life. So riding bikes can help you to  9  more about China and the Chinese people. Now people in the world say China is the country of bikes because there are  10  bikes in China. I hope people all round the world like them.

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

单项选择题