$n_{(C_{17}H_{31}COO)_3C_3H_5}=\dfrac{175,6}{878}=0,2(mol)$
$\to n_{C_{17}H_{31}COONa}=n_{NaOH}=3n_{\text{este}}=0,2.3=0,6(mol)$
$V=\dfrac{0,6}{1}.1000=600ml$
$m=0,6.302=181,2g$
$\to m'=181,2:80\%=226,5g$
Tìm 30 tính từ miêu tả cuộc sống đô thị
Tìm các số tự nhiên x: 27 : (2x+1)
Tìm ba cặp từ trái nghĩa nói về việc ăn uống. Đặt câu vs một trong ba cặp từ đó Các bn làm nhanh giúp mik nha mik đang cần gấp
The (1) of handicrafts is often forgotten. Handicrafts reflect a country's culture and traditional. For centuries, it has (2) an important role in preserving folk art, cultural heritage and history. Handicrafts also present an interesting way to addition, teach young people and foreigners about a country's culture (3) handicraft industry is good for the economy. Many traditional craft villages can succeed without too much financial investment (4) artisan often use old materials or cheap ones that can be found in nature. Traditional craft also provides emoloyment opportunities for many people in small villages. Furthermore, tourism benefits from handicraft industry because unique products with high cultural volue (5) very appealing to many foregners 1 A important B. importable C. importanly D. importance 2.A. played B. taken C. gotten D.done 3.A. For B. in C. with D.to 4.A because B. although C.however D.but 5. A. is B were C. are D. was va tai sao chon giai thich ho minh vs
Complete with a suitable relative pronoun. Omit the relative when possible. 1. The man ……………. lives next door won the lottery two months ago. 2. There is a hotel ………………………….. gives their customers free meals on Sundays. 3. The chair ……………………….. Ann bought at the sales is not very comfortable. 4. The man with ………………… you went to London has called while you were out. 5. The children …………………….teacher is Mr Pitt are a bit naughty. 6. The letter …………………. I left on the kitchen table was for dad. 7. The party ………………………John and Paul went to was a bit boring. 8. The dress ………………………I was wearing at my sister’s wedding was not mine. Lisa lent it to me for the special occasion. 9. Yesterday I met a man ……………………….wife can speak eight languages. 10. This is the girl …………………………….I used to look after when her parents went out at night. 11. They broke the vase ………………………….. they had bought when they went to China. 12. My neighbours have bought a car…………………………seats are made of leather. 13. The robbery ………………………….they are talking about took place yesterday night. 14. The music to ………………….which I like listening is a bit noisy. 15. The old lady……………………..was run over by a van has just died in hospital. 16. The letter ……………………….Helen is writing now is for his Spanish penfriend. 17. The woman ……………………you are looking for doesn’t work here any more. 18. The food ………………………….they serve in this restaurant is the best in town. 19. They caught the thief ………………………had stolen the diamond three days after the robbery. 20. Spiders are animals ………………………have eight legs. 21. Could you tell me the shelf…………………………you put the book on? 22. The computer……………………. my parents bought me for my birthday has just crashed. 23. The museum …………………….Alice took me to the other day was really interesting. 24. The wallet ……………………………….my brother found in the street was full of money. 25. The man …………………………..I borrowed the book from is a friend of my father’s. 26. The subject ……………………….. Mary likes best is geography. She’s very good at it. 27.The plane ……………………….. we were waiting for was delayed because of the thick fog. 28. The flat in ……………………………….Frank lived before was in the town centre. 29. The mobile phone ………………..is ringing is not mine. Mine has got a different ringtone. 30. The fortune teller .. ………………………..I went to turned out to be a fake
$x_{1}$,$x_{2}$ là hai nghiệm của phương trình x ²-3x+1=0 cmr $S_{2k+1}$=$x_{1}^{2k+1}$ +$x_{1}^{2k+1}$-2 là số chính phương
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Lm đc j lm nấy thou ạ, ko nhất thiết phải lm hết, cần gấp💦💦💦 Xin cảm ơn
I.Put the verbs in brackets in the present perfect or the simple past tense. 1. We (never watch) that TV programme. 2. We (watch) a good programme on TV last night. 3. He (read) that novel many times before. 4. He (read) that novel again during my last vacation. 5. I (have) a little trouble with my car last week. 6. However, I (have) no trouble with my car since then. 7. I (not see) John for a long time. I (see) him 3 weeks ago. 8. The school bell (ring) . We must go now. 9. I (meet) Mary last night. She (become) a very big girl. 10. He is very thirsty. He (not drink) since this morning. II.Give the correct form of the verbs in the present perfect. 1. Tom (see) this film before. 2. I (finish) my exercise already. 3. They (live) here since 1990. 4. My father (just wash) his car. 5. The students (discuss) the question recently. 6. Mary (never, be) to Ha Noi. 7. We (know) each other for 5 years. 8. So far we (learn) five lessons. 9. We (be) pen pals for a long time. 10. They (stay) here since last week. cần gấp ạ
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