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21 tháng 3 2021

Câu 1 : 

\(a) 2KMnO_4 \xrightarrow{t^o} K_2MnO_4 + MnO_2 + O_2\\ b) Na_2O + H_2O \to 2NaOH\\ c) 4Al +3 O_2 \xrightarrow{t^o} 2Al_2O_3\\ d) 2Fe(OH)_3 \xrightarrow{t^o} Fe_2O_3 + 3H_2O\\ e) 2Al + 3H_2SO_4 \to Al_2(SO_4)_3 + 3H_2\)

- Phản ứng phân hủy : a ; d

- Phản ứng hóa hợp : b ; c

- Phản ứng thế : e

Câu 2 : 

\(4P + 5O_2 \xrightarrow{t^o} 2P_2O_5\\ 3Fe + 2O_2 \xrightarrow{t^o} Fe_3O_4\)

21 tháng 3 2021

Câu 3 : 

\(a) 3Fe + 2O_2 \xrightarrow{t^o} Fe_3O_4\\ b) n_{Fe} = \dfrac{126}{56}= 2,25(mol)\\ \Rightarrow n_{O_2} = \dfrac{2}{3}n_{Fe} = 1,5(mol)\\ \Rightarrow V_{O_2} = 1,5.22,4 =33,6(lít)\\ c) 2KClO_3 \xrightarrow{t^o} 2KCl + 3O_2\\ n_{KClO_3} = \dfrac{2}{3}n_{O_2} = 1(mol)\\ m_{KClO_3} = 1.122,5 = 122,5(gam)\)

19 tháng 11 2021

15 They said they would go to the beach if the weather was nice the day after (loại 1)

16 I told Mike Halen would know what to do if she were late (2)

17 Mark said he would have spoken to Frank if he had seen him the day before (3)

18 The girl said he wouldn't run away if she saw a spider (2)

19 David told her if she had too much to do, she could ask him to help her (2)

20 He told me if I studied harder, I would get high marks in next exam (1)

14 tháng 10 2021

12) \(4C_xH_y\left(COOH\right)_2+\left(2x+y+2\right)O_2\xrightarrow[]{t^o}\left(4x+8\right)CO_2+\left(2y+4\right)H_2O\)

13) \(2KHCO_3+Ca\left(OH\right)_2\rightarrow K_2CO_3+CaCO_3+2H_2O\)

14) \(Al_2O_3+6KHSO_4\rightarrow Al_2\left(SO_4\right)_3+3K_2SO_4+3H_2O\)

15) \(xFe_2O_3+\left(3x-2y\right)H_2\xrightarrow[]{t^o}2Fe_xO_y+\left(3x-2y\right)H_2O\)

28 tháng 4 2021

1 My sister has learned English for 5 years

2 A supermarket was built near the airport last year

3 I spent three hours cleaning the house yesterday

6 The wall built three weeks ago fell down

7 Unless you leave me alone, I will call the police

8 The suspects are being followed by the police 

10 Nobody in this team is as good at playing football as Tom

28 tháng 4 2021

gần hết còn gi? :))

10 tháng 3 2022

3A

4B

5D

10 tháng 3 2022

3C

4D

5D

6C

khôn zị ai chơi lại-.-''

24 tháng 12 2021

Thật là ít

15 tháng 6 2021

16 B

17 A

18 C

19 B

20 B

15 tháng 6 2021

11 D

12 C

13 A

14 C

15 C

16 B

17 A

18 C

21 tháng 5 2021

1 I asked her if she had met my friend

2 He asked me if I could swim

3 Nam told Lan he was writing to her friend that night

4 They told him they gave him a pen

5 Peter told Mary her father had just come to his house

6 Mr Hiep told the pupils he often gave them good advice

7 She told him she had met him at the beach the day before

8 Nam asked Hong if she had been tired the day before

1 She asked Nam where he was going

2 They asked Hoa what her friend had read

9 I asked Peter why he went to her house

10 Lan asked Huong when she would visit her friend?

11 He asked her what her name was

12 Yom asked Mart where she had met his sister

13 Peter asked Daisy if she was writing to his brother

14 Peter told Mary to bring him her pen

15 She told him not to tell her brother about it

16 Mai told Huong to go to her friend's house with her

17 Hong told Nam to try his best

18 He told me not to go out alone at night

19 He asked me if I visited his friend often

20 She asked me if I liked her

21 He asked Hoa what had made her sad

22 Mr Pike asked Mary where she often went

23 She said she would go to visit Nha Trang

24 Mary told Tom she had seen his friend going with her friend

25 I said I would go to visit her

26 Lan told me she gad read my book ten days before

27 Hoa told Hung she had been writing to him

28 She asked him why he hadn't gone to the party the day before

29 Peter asked Daisy where they were going to meet each other the next Sunday

30 he asked Hoa of she had met her friend

21 tháng 5 2021

1. I asked her if she had met my friend.

2. He asked me if I could him.

3. Nam said to Lan that he was writing to her friend that night.

4. They offered to give him a pen.

5. Peter said to Mary that her father had just come to his house.

6. Mr Hiep said to the pupils that he often gave them good advice.

7. She said to him that she had met him the day before.

8. Nam asked Hong if she had been tired the day before.

1. She asked Nam where he was going.

2. They asked Hoa what her friend had read.

9. They asked Peter why he didn't go to her house.

10. Lan asked Huong when she would visit her friend.

11. He asked her what her name was.

12. Tom asked Mary where she had met his siter.

13. Peter asked Daisy if she was writing to his brother.

14. Peter asked Mary to bring him her pen.

15. She asked him not to tell her mother about it.

16. Mai asked Huong to go to her friend's house with her.

17. Huong encouraged Nam to try his best.

18. He warned her not to go out alone at night.

19. He asked me if I visited his friend often.

20. She asked me if I liked her.

27 tháng 11 2021

1.What

2.a

3.How are you?

4.Are

5.there

6.what is that

...

bài này của lớp 6?