Nguyễn Thị Minh Nguyệt

Hình như đề có vấn đề nha bạn

a) Mg + 2HCl ➝ MgCl₂ + H₂

MgO + 2HCl ➝ MgCl₂ + H₂O

Từ PTHH: nMg = nH₂ = 0,1 mol => mMg = 2,4 g

=> mMgO = 3,6 g => %mMgO = 60 %

b) nHCl = 2nMg + 2nMgO = 2.0,1 + \(\frac{2.3,6}{40}\) = 0,38 mol

=> mHCl = 13,87 g => m_dd = 69,35 g

=> V_ddHCl ≃ 63 lít

Do p = e nên theo đề ra, ta có hệ phương trình:

\(\left\{{}\begin{matrix}2p+n=34\\n-p=1\end{matrix}\right.< =>\left\{{}\begin{matrix}p=11\\n=12\end{matrix}\right.\)

Vậy nguyên tố A là Natri. Kí hiệu: Na

Ta có: nK = 0,4 mol ; nH₂O ≃ 5,6 mol

a) PTHH: 2K + 2H₂O ➝ 2KOH + H₂

b) ban đầu :0,4---5,6

phản ứng: 0,4-----0,4

dư: 0-------5,2

=> K hết, H₂O dư, bài toán tính theo K

Theo PTHH: nH₂ = \(\frac{1}{2}\)nK = 0,2 mol => V = 4,48 lít

c) nKOH = nK = 0,4 mol => mKOH = 22,4 g

=> C%_KOH ≃ 19,4 %

Bạn kiểm tra lại đề bài đc ko chứ mk giải mà cứ thấy sai sai

1. Send/ will receive

2. Will go / has

3. Will spend / is

4. Doesn't phone / will leave

5. Go/ won't be

6. Has / Wil earn

1. Listen! An old tune is playing on radio

2. Nobody helped Mr.Green while the garage was being painted

3. Mary had had a bath before she was called by one of her friends yesterday

4. The accountant looks sad because the bills hasn't been paid yet

5. He felt sorry when he realized that his stamp collection had been stolen

6. If I were him, I wouldn't treat my father like that. He will sorry for that in the future

7. If she had seen me, she would have gotten angry with me, because I had promised to call her out but I didn't

8. He has stopped smoking since he had a heart attack

9. As soon as she finishes changing the baby'snappy, she will take the children to school

10. He said his car had already been mended

11. She said she would open her first exhibition the following month

12. Mary and Jow want to go to the shore which sounds like a good idea to me

13. He won't wake up on time unless he uses an alarm clock

Let the door be locked

The student apologized for being late

1. It's ages since I saw her

2. I haven't met George for two weeks

3. They arrived here three months ago

4. We have not met each other for five days

5. Haven't you tasted one before?

6. I haven't smoked a cigarette for ten years

7. It's two weeks since I last drank wine

8. I came to Istanbul in January

9. They have been to Ankara for two years

10. This is the first time she has been to Rome

1. pollute / will die

2. consists / will get

3. melt / will be

4. will disappear / cut down

5. is thrown / will be

6. continue / will be destroyed

7. will save / save

8. teach / will know

9. travel / won't have

10. fines / won't dump

1. I am given 10.000 VND by my mother every day

2. A new house was bought in this city by Mr,Brown two years ago

3. A new brigde was built in this village

4. The tickets are shown to the airline agent

5. This room is kept clean all the time

6. Some of my books were taken away

7. This room is usually used at weekend

8. Their project was finished a week ago

9. I am usually paid after 2 days

a) nNa = 0,84 mol

2Na + 2H₂O ➝ 2NaOH + H₂

0,84---------------------------0,42

nH₂ = 0,42 mol => V = 9,408 lít

b) nNaOH = nNa = 0,84 mol

=> mO = 13,44 gam => mA ≃ 17,9 gam

Gọi công thức phân tử của hợp chất là X₂O₅

Theo đề ra, ta có: 2X + 5.16 = 6.18 <=> X = 14

=> Nguyên tố X là Nitơ (N)

Trích mẫu thử và đánh số thứ tự

- Nhỏ lần lượt mẫu thử vào quỳ tím, ta được 3 nhóm:

+) Nhóm 1 (làm quỳ tím hóa đỏ): HCl

+) Nhóm 2 (làm quỳ tím hóa xanh): KOH, Ba(OH)₂

+) Nhóm 3 (không làm quỳ tím đổi màu): NaCl

- Cho mẫu thử hai chất nhóm 2 tác dụng với H₂SO₄, chất phản ứng tạo kết tủa là Ba(OH)₂

2KOH + H₂SO₄ ➝ K₂SO₄ + 2H₂O

Ba(OH)₂ + H₂SO₄ ➝ BaSO₄↓ + 2H₂O

a) CuO + H₂ ➝ Cu + H₂O

Fe₂O₃ + 3H₂ ➝ 2Fe + 3H₂O

Fe + H₂SO₄ ➝ FeSO₄ + H₂

Do Cu không phản ứng với H₂SO₄ nên chất rắn còn lại sau phản ứng là Cu => nCu = 0,05 mol

Từ PTHH: nCuO = nCu = 0,05 mol => mCuO = 4 g

=> %mCuO = 20 % => %mFe₂O₃ = 80 %

b) mFe₂O₃ = 16 g => nFe₂O₃ = 0,1 mol

Từ PTHH: nFe = 2nFe₂O₃ = 0,2 mol

=> nH₂ = nFe = 0,2 mol

=> V = 4,48 lít

a) mBaCl₂ = 20,8 g => nBaCl₂ = 0,1 mol

mH₂SO₄ = \(\frac{m_{dd}C\%}{100}\) = \(\frac{100.1,14.20}{100}\) = 22,8 g => nH₂SO₄ ≃ 0,2 mol

BaCl₂ + H₂SO₄➝ BaSO₄↓ + 2HCl

bđ: 0,1 0,2

pứ: 0,1 0,1

dư: 0 0,1

Vậy BaCl₂ hết, H₂SO₄ dư, bài toán tính theo BaCl₂

nBaSO₄ = nBaCl₂ = 0,1 mol

=> mBaSO₄ = 23,3 g

b) nHCl = 2nBaCl₂ = 0,1 mol

=> C_M = 1 M

nH₂SO_4dư = 0,1 mol => C_M = 1 M

a) nNaOH = 0,25 mol ; nHNO₃ = \(\frac{10}{63}\) mol

NaOH + HNO₃ ➝ NaNO₃ + H₂O

pứ: \(\frac{10}{63}\) \(\frac{10}{63}\)

bđ: 0,25 \(\frac{10}{63}\)

dư: 0,09 0

=> HNO₃ phản ứng hết, NaOH dư, bài toán tính theo HNO₃

Do dung dịch sau phản ứng có NaOH dư nên quỳ tím hóa xanh

b) nNaNO₃ = nHNO₃ = \(\frac{10}{63}\) mol

=> mNaNO₃ ≃ 13,5 gam

Fe + H₂SO₄ ➝ FeSO₄ + H₂

BaO + H₂SO₄ ➝ BaSO₄ + H₂O

Al₂O₃ + 3H₂SO₄ ➝ Al₂(SO₄)₃ + 3H₂O

2KOH + H₂SO₄ ➝ K₂SO₄ + 2H₂O

Fe + CuSO₄ ➝ Cu + FeSO₄

2KOH + CuSO₄ ➝ K₂SO₄ + Cu(OH)₂

Ta có: Khối lượng của 1 nguyên tử C = 1,9926.10^-23 gam

Mà: C = 12 đvC => 1 đvC = 1,6605.10^-24 gam

Khối lượng của 9,632.10²¹ nguyên tử Na là:

(9,632.10²¹).23.(1,6605.10^-24) ≃ 0,37 gam

Đề của bạn còn thiếu thì phải, bạn kiểm tra lại nha

Do p = e nên:

\(\left\{{}\begin{matrix}2p+n=100\\2p-n=40\end{matrix}\right.< =>\left\{{}\begin{matrix}p=35\\n=30\end{matrix}\right.\)

Vậy e = p =35 ; n =30

Do p = e nên:

\(\left\{{}\begin{matrix}2p+n=60\\p-n=0\end{matrix}\right.< =>\left\{{}\begin{matrix}p=20\\n=20\end{matrix}\right.\)\(\left\{{}\begin{matrix}2p+n=60\\p-n=0\end{matrix}\right.< =>\left\{{}\begin{matrix}p=20\\n=20\end{matrix}\right.\)

Vậy e = p = n = 20

1. Were => had been

2. Had done => have done

3. Has => had

4. Will study => study

5. Am = >were

6. Will=> would

7. To => X

8. Unless => If

9. Apply => have applied

10. Will=> would

Đây là chuyển từ câu trực tiếp sang gián tiếp mà

1. The man asked boys to be quiet

2. Ann asked him not to wait for her if she was late

3. Tom asked us to help him

4. I asked Nam to turn his light off and go to bed early

5. He said he would be there again the next day

6. He told them their houses are nicer than hí

7. She said he had lived her for 4 years

8. Tom told me he was going away for a few days and would phone me when he got back

9. He said he had seen her that morning

10. Betty told Bill she didn't like that film

11. Tom said he had seen John the day before but he hadn't seen Tom

12. She told her mother she hadn't seen her since she had come there

13. Mary told John she couldn't go to the movie with him the next week

14. William told Lan she was very grateful to her for her helping him with the vietnamese lesson

There isn't much entertainment for young people in this village in the evening

1. Ha Noi is one of the most famous cities in Viet Nam

2. The foot here are long

3. He is very hungry but he doesn't eat it

4. They have a lot of bad marks because they are lazy