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Thanh Thảo
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Phạm Uyên
24 tháng 5 2021 lúc 11:25

III. 

A. 

1. B

2. C

3. B

4. A

5. D

B. 

1. C

2. B

3. B

4. A

5. C

Mai Thị Kiều Nhi
18 tháng 11 2021 lúc 20:30

1 b c b a d

2 c b b a c nha

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Thanh Thảo
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Đỗ Thanh Hải
24 tháng 5 2021 lúc 11:14

1 The meeting was canceled 3 days ago

2 She told me she was watching a film with her sister then

3 I admire the guitarist who is perfroming on the stage

4 Had it not been for Pauline's interest, the project would have been abandoned 

Phạm Uyên
24 tháng 5 2021 lúc 11:20

IV. 

1. The meeting was canceled 3 days ago.

2. She told me shewas watching a film with her sister then

3. I admire the guitarist who is performing on the stage

4. Had it not been for Pauline's interest, the project was abandoned. (chắc thế)

Con mèo
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Khinh Yên
3 tháng 8 2021 lúc 17:17

He asked me to know what the time was.

She asked me when we would meet again.

She asked him If he was crazy.

He asked me to know when they had lived.

He asked her If she would be at the party.

She asked me If I could meet her at the station.

The teacher asked me to know who knew the answer

She asked him to know why he didn't help her.

He asked me If I had seen that car.

The mother asked the twins If they had tidied up their room.

Tom asked how much that computer was

Lê Trang
3 tháng 8 2021 lúc 17:18

11. what the time was.

12. when they would meet again.

13. if he was crazy.

14. where they had lived.

15. if she would be at the party.

16. if I could meet her at the station.

17. who knew the answer.

18. why I didn't help her.

19. if I had seen that car.

20. if they had tidied up their room.

Bài 3:

asked how much that computer was.

Thanh Thảo
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Edogawa Conan
19 tháng 9 2021 lúc 12:48

Ta có: \(\left\{{}\begin{matrix}p+e+n=52\\p=e\\n-p=1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}p=e=17\\n=18\end{matrix}\right.\)

khai nguyen
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Nguyễn Việt Lâm
6 tháng 1 2022 lúc 17:52

A là đáp án đúng

layla Nguyễn
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Ánh Ngọc
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santa
2 tháng 4 2022 lúc 8:42

Câu 2 :

a) PTHH : \(2Al+3S-->Al_2S_3\)

               \(Zn+S-->ZnS\)

mS = 29,55 - 15,15 = 14,4 (g)

b) nS = 14,4/32 = 0,45 (mol)

PTHH : \(Al_2S_3+3H_2SO_4-->Al_2\left(SO_4\right)_3+3H_2S\)

                \(ZnS+H_2SO_4-->ZnSO_4+H_2S\)

               \(H_2S+2AgNO_3-->Ag_2S+2HNO_3\)

Bảo toàn S : nAg2S = nH2S = nS = 0,45 (mol)

=> mktAg2S = 111,6 (g)

c) PTHH : \(H_2S+CuCl_2-->CuS+2HCl\)

nH2S = 0,45/2 = 0,225 (mol)

Theo pthh : nCuS = nH2S = 0,225 (mol)

=> mCuS = 0,225.96 = 21,6 (g)

Ánh Ngọc
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๖ۣۜDũ๖ۣۜN๖ۣۜG
25 tháng 3 2022 lúc 23:36

Gọi số mol Mg, Zn là a, b (mol)

\(n_{H_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)

PTHH: Mg + 2HCl --> MgCl2 + H2

            a---------------->a----->a

            Zn + 2HCl --> ZnCl2 + H2

             b--------------->b---->b

=> a + b = 0,3 (1)

Và 95a + 136b = 36,7 (2)

(1)(2) => a = 0,1 (mol); b = 0,2 (mol)

\(\left\{{}\begin{matrix}\%m_{Mg}=\dfrac{0,1.24}{0,1.24+0,2.65}.100\%=15,6\%\\\%m_{Zn}=\dfrac{0,2.65}{0,1.24+0,2.65}.100\%=84,4\%\end{matrix}\right.\)

Ánh Ngọc
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Kudo Shinichi
30 tháng 3 2022 lúc 21:29

a, Hiện tượng: mất dần màu vàng lục của Clo, có khí không màu thoát ra

\(K_2CO_3+Cl_2\rightarrow KCl+KClO+CO_2\uparrow\)

b, \(F_2+H_2\xrightarrow[\text{nhiệt độ âm}]{\text{bóng tối}}2HF\)

\(Cl_2+H_2\underrightarrow{as}2HCl\)

\(Br_2+H_2\underrightarrow{t^o}2HBr\\ I_2+H_2\underrightarrow{t^o,xt}2HI\)