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a) PTHH : Fe + H2SO4 -----> FeSO4 + H2 ( Vì Cu là kim loại yếu không tác dụng được với axit loãng nên bài này chỉ có 1 PT )
\(nH_2=\frac{4,48}{22,4}=0,2\left(mol\right)\)
Theo PT : \(n_{Fe}=n_{H_2}=0,2\left(mol\right)\)
\(\Rightarrow m_{Fe}=n.M=0,2\times56=11,2\left(g\right)\)
\(\%m_{Fe}=\frac{11,2}{30}\times100=37,3\%\)
\(\%m_{Cu}=100-37,3=62,7\%\)
b) Đổi 150ml = 0,15 l
Theo PT : \(n_{H_2SO_4}=n_{H_2}=0,2\left(mol\right)\)
\(\Rightarrow C_M=\frac{n}{V}=\frac{0,2}{0,15}\approx1,4\left(M\right)\)
a) Polime là những chất có phân tử khối lớn.
b) Polime là những chất có phân tử khối nhỏ.
c) Polime là những chất có phân tử khối rất lớn do nhiều loại nguyên tử liên kết với nhau tạo nên.
d) Polime là những chất có phân tử khối rất lớn do nhiều mắt xích liên kết với nhau tạo nên.
Chọn d) =))
- Dòng chứa tất cả các axit là dòng D.
- Tên các axit đó là
- \(H_3BO_3\) - Axit boric
- \(H_2SO_4\) - Axit sunfuric
- \(H_2SO_3\) - Axit sunfurơ
- \(HCl\) - Axit clohydric
- \(HNO_3\) - Axit nitric
Vừa qua nó bị lỗi dòng, cô gửi lại nhé:
Dòng chứa tất cả các chất axit là dòng D.
\(H_3BO_3-\text{Axit boric}\)
\(H_2SO_4-\text{Axit sunfuric}\)
\(H_2SO_3-\text{Axit sunfurơ}\)
\(HCl-\text{Axit clohiđric}\)
\(HNO_3-\text{Axit nitric}\)
Bài số 1
Mid-Autumn Festival is under the full moon day of the lunar calendar every year in August, over 4,000 years ago. This is the day children’s festival, also known as the “Festival looks Moon”. Children are expected Tet is because adults are often donated toys, usually light. His star, mask, light pull troops … and pies, cakes plas. Besides the Tet Holiday, Mid-Autumn festival is one of the most famous festivals and it is a traditional celebration for Vietnamese children.
In this new year, we organized presentation deck, looks moon. Everywhere is fallen in the active and colorful air. Children are provided with many nice lanterns – star lanterns, flower lanterns and diverse funny masks for special performance in the evening of the full moon. In some areas, people also held dragon dance, lion dance to the children happy. The main point of the Mid-Autumn is that children use the beautiful lanterns, wear funny masks, perform fantas lion dances and sing folklore songs in the house’s grounds or on the streets when the moon is rising.
In Vietnam, Moon cakes are the specific cakes and are only on this festival. Moon cakes, which are made from flavor, dried fruit, meat, egg, pumpkin’s seed, peanut, are so sweet and good tasting. Moon cakes symbolize Luck, Happiness, Health and Wealth on the Mid-Autumn day.
Mid-Autumn celebration is also an opportunity for members of the family to get together and share everything in their year. The young generation express their gratitude to the old generation. The parents show their love for their children. For others, because the traditional time to have this festival is usually after harvesting the crops, it is as the congratulation for the full harvest.
Apart from moon cakes and lanterns, the other most visible tradition related to Mid-Autumn festival is the lion dance. On the nights leading up to the holiday, groups of children parade through the streets – some of the children maintain a martial beat on drums, while others control an extravagantly decorated ‘lion’ crafted from molds and paper.
The children approach homes and businesses and ask the owners for their permission to perform. If they agree, the children put on a show that is believed to bring a blessing of luck and fortune. Afterwards the host gives the children lucky money as a sign of gratitude.
Bài số 2
The Mid-Autumn festival dates back to the Rice Civilization of the Red River delta, over 4,000 years ago. It is held on the 15th day on the 8th lunar month (often in late September or early October) in the middle of autumn and it is celebrated for a whole day. Besides the Tet Holiday, Mid-Autumn festival is one of the most famous festivals and it is a traditional celebration for Vietnamese children.
Children are provided with many nice lanterns - star lanterns, flower lanterns and diverse funny masks for special performance in the evening of the full moon. Everywhere is fallen in the active and colorful air. The main point of the Mid-Autumn is that children use the beautiful lanterns, wear funny masks, perform fantas lion dances and sing folklore songs in the house's grounds or on the streets when the moon is rising.
Moon cakes are the specific cakes and are only on this festival. Moon cakes, which are made from flavor, meat, egg, dried fruit, pumpkin's seed, peanut, are so sweet and good tasting. Moon cakes symbolize Luck, Happiness, Health and Wealth on the Mid-Autumn day.
Apart from moon cakes and lanterns, the other most visible tradition related to Mid-Autumn festival is the lion dance. On the nights leading up to the holiday, groups of children parade through the streets – some of the children maintain a martial beat on drums, while others control an extravagantly decorated 'lion' crafted from molds and paper.
The children approach homes and businesses and ask the owners for their permission to perform. If they agree, the children put on a show that is believed to bring a blessing of luck and fortune. Afterwards the host gives the children lucky money as a sign of gratitude.
Mid-Autumn celebration is also an opportunity for members of the family to get together and share everything in their year. The young generation express their gratitude to the old generation. The parents show their love for their children. For others, because the traditional time to have this festival is usually after harvesting the crops, it is as the congratulation for the full harvest.
5. You can speak English fluently, __________?
A. could you | B. can’t you | C. can you | D. couldn’t you |
6. On average, _________Moon is 384.400 km from ___________ Earth.
A. the-the | B. x-the | C. a-an | D. a-the |
7. _________ my opinion, he is the best football player in our team.
A. On | B. At | C. In | D. From |
8. On March 8th , women often _____ beautiful roses, postcards, lots of gifts with the best wishes from their relatives and friends.
A. give | B. send | C. have | D. receive |
9. The driver stopped ______ a coffee because he felt sleepy.
A. have | B. to have | C. having | D. had |
10. I wish I ______ play football well.
A. can | B. could | C. am | D. did |
11. If I ________ you, I would join this English Speaking Contest.
A. were | B. am | C. would be | D. will be |
12. _______ there is a lot of noise in the city, I living there.
A. Because | B. Despite | C. In spite of | D. Although |
13. I suggest ________ a shotcut through the field . It will take much less time.
A. take | B. taking | C. to take | D. takes |
14. She has a lot of ___________ while she’s studying English.
A. difficult | B. difficulties | C. difficile | D. diffident |
15. He finds the way to a place easily. He was a very good sense of ___________
A. direction | B. humor | C. style | D. responsibility |
16. There are lots of people who _____ work in remote and mountainous areas nowadays.
A. volunteers | B. voluntary | C. voluntarily | D. volunteer |
17. If you want to _____ the other students in your class, you’ll have to work very hard.
A. catch up with | B. learn on | C. catch up | D. hurry up |