问题 问答题

(1)0.5L 1mol/L FeCl3溶液与0.2L1mol/L KCl溶液中的Cl-的数目之比______

(2)将标准状况下的a升氯化氢气体溶于1000克水中,得到的盐酸的密度为b克/毫升,则该盐酸的物质的量的浓度是______

(3)同温同压下,气体A与氧气的质量比为1:2,体积比为1:4,气体A的相对分子质量是______.

答案

(1)0.5L 1mol/L FeCl3溶液中c(Cl-)=3c(FeCl3)=3×1mol/L=3mol/L,n(Cl-)=0.5L×3mol/L=1.5mol;0.2L 1mol/L KCl溶液中c(Cl-)=c(KCl)=1mol/L,n(Cl-)=0.2L×1mol/L=0.2mol,所以数目之比等于1.5mol:0.2mol=15:2,故答案为:15:2,

(2)氯化氢的物质的量n=

aL
22.4L/mol 
=
22.4 
mol,氯化氢的质量m=n×M=
22.4
 mol
×36.5g/mol=
36.5a 
22.4
g,

溶液的体积V=

ρ
=
1000+
36.5a 
 22.4
bg•cm-3 
ml=
22.4×103+36.5a 
22.4b 
×10-3L

则C=

=
22.4 
mol
 22.4×103+36.5a 
22.4b 
10-3L 
 
 
 
=
1000ab
22400+36.5a
mol/L,故答案为:
1000ab
22400+36.5a
mol/L.

(3)因同温同压下,体积比为等于物质的量之比,所以气体A与氧气的摩尔质量之比=

1
1
2
4
=2:1,氧气的摩尔质量为32g/mol,所以气体A的摩尔质量为64g/mol,相对分子质量64,故答案为:64.

阅读理解

阅读理解。

     Early one morning the subinspector at a station at the other end of the town rang me. An

elephant was damaging the town. Would I please come and do something about it?

     I did not know what I could do, but I got onto a horse and started out.  I took my gun,

maybe too small to kill an elephant, but I thought the noise might scare him. Various local

people stopped me on the way and told me about the elephant's doings.

     It was not, of course, a wild elephant, but a tame one. It had been chained up but last

night it had broken its chain and escaped. Its owner had set out to run after it, but had taken

the wrong direction. He was now twelve hours' journey away, and in the morning the elephant

had suddenly appeared in the town. It had already destroyed somebody's bamboo hut (棚屋),

killed a cow and turned over fruitstalls.

     I came round the hut and saw a man's dead body sprawling in the mud.  He was an Indian,

and he could not have been dead many minutes. The people said that the elephant caught him

with its trunk, put its foot on his back and grounded him into the earth. This was the rainy season

and he was lying on his stomach in the soft mud, the peacebreaker standing beside, looking

innocent.

     As I lifted my gun, I hesitated a few seconds. Then I fired. That was a shot that did for him.

     You could see the pain of it knock the last strength from his legs. But in falling he seemed for

a moment to rise, his trunk reaching skyward like a tree. He trumpeted, for the first and only time. 

And then down he came, with a crash that shook the ground.

1. Which of the following statements about the author is TRUE?

A. He was an Indian.

B. He knew elephants well.

C. He was not a local villager.

D. He was the owner of the elephant

2. The elephant made so much trouble because ________.

A. its owner treated him cruelly

B. it got out of control

C. it hated the village people

D. it was a wild elephant

3. The underlined words "the peacebreaker" in Paragraph 4 refer to ________.

A. the elephant              

B. the dead man

C. the author                

D. the subinspector

4. It can be inferred that the author felt ________ when he shot the elephant.

A. excited    

B. sad        

C. frightened   

D. happy

单项选择题