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22 tháng 10 2021

lập nick mới là vừa

22 tháng 10 2021

muốn báo cáo đúng ko???

Free cho 1 vé luôn

Hàng Víp luôn

22 tháng 10 2021

TL:

PT

TK CHO M

HT

22 tháng 10 2021

ok bạn

20 tháng 1 2022

dgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgdgx

Phân tử hợp chất tạo bởi 2 nguyên tử X kết hợp với 1 nguyên tử O,trong đó nguyên tử O chiếm 25,8% về khối lượng.X là nguyên tố:

A.Na

B.Li

C.K

D.Ca

Hòa tan hoàn toàn 1,2g MgO vào 300 ml dd H2SO4

a.      Tính nồng độ mol của axit đã dùng

b.      Tính khối lượng muối tạo thành.

22 tháng 10 2021

a)nMgOnMgO=6:40=0,15(mol)

Ta có PTHH:

MgO+H2SO4H2SO4->MgSO4O4+H2OH2O

0,15......0,15...........0,15..................(mol)

Theo PTHH:mH2SO4mH2SO4=0,15.98=14,7g

b)Ta có:mddH2SO4mddH2SO4=D.V=1,2.50=60(g)

=>Nồng độ % dd H2SO4H2SO4 là:

C%ddH2SO4C%ddH2SO4=14,76014,760.100%=24,5%

c)Theo PTHH:mMgSO4mMgSO4=0,15.120=18(g)

Khối lượng dd sau pư là:

mddsaumddsau=mMgOmMgO+mddH2SO4mddH2SO4=6+60=66(g)

Vậy nồng độ % dd sau pư là:

C%ddsauC%ddsau=18661866.100%=27,27%

21 tháng 1 2022

gvvvvvvvvvvvvvvvvvvvvvvvvvvft

10 tháng 1 2022

PTHH:

\(MgO+2HCl\rightarrow MgCl_2+H_2O\)

\(Mg\left(OH\right)_2+2HCl\rightarrow MgCl_2+2H_2O\)

Exercise 8: Read the text and do the tasks that follow.Houses for lease#1 I have a beautiful double bedroom available in an apartment to share with one other person. The apartment is on the 12th floor and the room itself is a large double bedroom with two big beds under the window. There is a lamp and a chest of drawers between the two beds. In the corner of the room, there is also a wardrobe and a bookshelf. The apartment has a modern kitchen and an open living room. It is only a 5-minute walk...
Đọc tiếp

Exercise 8: Read the text and do the tasks that follow.

Houses for lease

#1 I have a beautiful double bedroom available in an apartment to share with one other person. The apartment is on the 12th floor and the room itself is a large double bedroom with two big beds under the window. There is a lamp and a chest of drawers between the two beds. In the corner of the room, there is also a wardrobe and a bookshelf. The apartment has a modern kitchen and an open living room. It is only a 5-minute walk to the bus stop. A one month deposit is needed, but there are no other fees.

 

#2 We have a large unfurnished double room, in a really nice house in the city. It's a big and clean house with a beautiful street view. The house is a 10-minute walk from the station. There is a shared living room, bathroom and kitchen with an air-conditioner, two ceiling fans, a microwave, a television and four armchairs. The minimum term is three months and the deposit is one month's rent.

#3 The room is in a two bedroom house that is very close to the bus stop going to the town. There is a kitchen next to the room and it's furnished including a dishwasher. There are also two large modern bathrooms with separate showers. The room is facing the garden and it is nice and quiet. It's good for people who enjoy a quiet but sociable life. The house is occupied by a mother and her 10-year-old son. Both are very nice and friendly. The rent is all inclusive - no more charges.

1. Match the following titles with the corresponding paragraphs.

1. A Nice Double Room To Rent Within A Modern Apartment

2. A Double Room To Rent In A Big House, Very Close To The Station

3. A Double Room In A Quiet Area

Paragraph 3

Paragraph 2

Paragraph 1

 

2. Fill in the blank with number 1, 2, or 3 corresponding to the three houses mentioned in the passage.

1.____________ There are 2 beds in the bedroom.

2. ____________It is very near the bus stop to the town.

3. ____________You must rent it at least 3 months.

4. ____________You will live with another person if you rent this house/ apartment.

5. ____________There isn't any furniture in this room.

6. ____________The kitchen is next to the bedroom.

7. ____________There are two bedrooms in this house/ apartment.

8. ____________You will live with a woman and a boy in this house/ apartment.

9. ____________It takes you about five minutes to walk to the bus stop.

10. ____________You will share the bathroom and the kitchen with others in this house/ apartment.

3. Choose the best answer to complete the blank.

1. You have to pay one month in advance if you rent the house/ apartment ________.

A. 1 & 2                           B. 2 & 3                            C. 1 & 3

2. You can see the street if you rent the house/ apartment ________.

A. 1                                   B. 2                                   C. 3

3. The kitchen in the house/ apartment ________ is furnished.

A. 1 & 2                           B. 2 & 3                            1 & 3

1
21 tháng 1 2022

tttttttttttttdhgj

11 tháng 1 2022

PTHH: \(CaCO_3+2HCl\rightarrow CaCl_2+H_2O+CO_2\uparrow\)

\(44,8ml=0,0448l\)

Có \(n_{CO_2}=\frac{m}{M}=\frac{0,0448}{22,4}=0,002mol\)

Dựa vào PTHH \(n_{CaCO_3}=n_{CO_2}=0,002mol\)

\(m_{CaCO_3}=0,002.100=0,2g\)

\(\rightarrow CaCO_3=\frac{0,2}{5}.100=4\%\)

\(\%CuSO_4=100-4=96\%\)