1B

2 C

3 B

4 C

5 D

III

1 A

2 D

3 C

4 C

5 C

6 B

7 A

8 B

9 D

10 A

11 C

12 C

13 B

14 C

15 D

16 C

17 C

18 A

19 D

20 B

21 D

22 D

23 A

24 A

PTHH: \(Na+H_2O\rightarrow NaOH+\dfrac{1}{2}H_2\uparrow\)  (1)

            \(Al+NaOH+H_2O\rightarrow NaAlO_2+\dfrac{3}{2}H_2\uparrow\)  (2)

Ta có: \(n_{H_2\left(1\right)}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\)

\(\Rightarrow n_{Na}=0,8mol\) \(\Rightarrow m_{Na}=0,8\cdot23=18,4\left(g\right)\)

Mặt khác: \(n_{H_2\left(2\right)}=\dfrac{15,68}{22,4}=0,7\left(mol\right)\)

\(\Rightarrow n_{Al}=\left(0,7-0,4\right)\cdot\dfrac{2}{3}=0,2\left(mol\right)\) 

(Vì Na là kim loại rất mạnh nên cũng sẽ tác dụng với nước trong dd NaOH dư và giải phóng khí H₂ nên phải trừ số mol của H₂ của Na)

\(\Rightarrow m_{Al}=0,2\cdot27=5,4\left(g\right)\)

\(\Rightarrow m=5,4+18,4=23,8\left(g\right)\)

đâu ?

I 1D 2C 3B 4A 5D 6B 7D 8A 9C 10C

III 1D 2C 3A 4B 5A 6C 7B 8B 9C 10C 11A 12B 13C 14A 15A 16B 17A 18D 19B 20C 21C

V  1C 2D 3B 4D 5C 6B 7C 8D 9A 10A

VII

playing

repairing

learning

having

to do

to choose

listening

playing

to read

chatting

VIII

I wish I weren't bisy 

She wish she had a bike

We used to play soccer in the afternoon

three hundred people are invited to the wedding by mary and Tom

I haven't seen her for 10 months

We wish we could go out

I wish she went to my bỉthday party

We used to go camping together

Two millions book are sent to .....

We haven't met each other for five years

1 He told me he had something to show me then

2 She said se was leaving there for Hue the next day

3 Tom told her he would come with her as soon as he was ready

4 The father told us he had to go then

5 she asked me why I came there late

6 peter asked me who put the salt in his cup of coffee

7 He asked the girl if she could play the piano

8 Maryam said that she was having a good time there

9 Hoa asked Maryam is she liked pop music

10 The man asked the boy where he lived

VII

1 had bought

2 was

3 had sold

4 passed

5 could

6 would sell

7 had gone

8 hadn't done

9 was listening

10 had to

VIII

1know   2what   3subjects  4written  5many   6in   7understanding   8friendship

IX

It's high time we went home

Unless you have a jacket and tie, you can't go to this restaurant

It was such a difficult question that no one could answer it

This letter hasn't been finished yet

5 Because he isn't good at English, he can't get a job