Cho 32,28 gam hỗn hợp X gồm (KAl(SO4)2.12H2O (phèn chua); K2SO4; Al2(SO4)3) vào nước được dung dịch Y. Chia Y thành 2 phần bằng nhau: Phần 1 cho vào dd Ba(OH)2 dư thu được 19,805 gam kết tủa Phần 2 cho vào dd NH3 dư thu được 3,51 gam kết tủa. Tính thành phần phần trăm về khối lượng của phèn chua trong hỗn hợp X? A. 74,52% B. 73,42% C. 69,04% D. 63,52%
1)tính nồng độ% của các dung dịch sau a)20 gam KCl trong 600 gam dung dịch b)32 gam KNO3 trong 2 Kg dung dịch c)Hòa tan 75g K2CO3 trong 1425 gam nước 2)Cho bao nhiêu gam NaOH vào bao nhiêu gam nước để có 200 gam dung dịch NaOH 10%
Trả lời câu 2 giúp tớ vs nhớ cho vd vì sao nha m.ng
1. The baby_____ his food onto the floor and making his mother angry. A. always threw B. is always throwing C. has always thrown D. always throws 2. I would like_____to Africa. A. go B. to go C. going D. to going 3. ____ is a building or room where people can go to look at paintings. A. Gallery B. Library C. University D. Gym 4. I brought back this cowboy hat as a ______ of America. A. gift B. present C. award D. souvenir 5. While Angela was cleaning her room, she _____ her lost earring. A. is finding B. finds C. has found D. found 6. Why don’t you come _____ for dinner? A. about B. over C. up D. upon 7. I picked up a copy of their summer travel_____. A. paper B. magazine C. book D. brochure 8. _____ is hot liquid rock that comes out of a volcano. A. Limestone B. Marble C. Lava D. Ice 9. We went_____ a 10-day tour of central Africa. A. in B. on C. at D. from 10. As Bob was driving to work, he _____ a wonderful idea. A. has B. has had C. had D. was having 11. The tour______ a visit to the Science Museum. A. had B. included C. enclosed D. included of 12. The statue_____ out of stone. A. carves b. was carved C. paints D. was painted 13. Ann ________ television when the phone rang. A. watches B. watched C. has watched D. was watching 14. Mary: ‘I think I’ll stay here after all.’- Peter: ‘You ______your mind.’ A. always change B. has always changed C. always changed D. are always changing 15. Oil poured_____ of the damaged ship. A. out B.off C. over D. upon 16. Jack _____ his homework between 8 pm and 9 pm. A. did B. was doing C. made D. was making 17. ____ is an area of land between hills or mountains. A. Valley B. Beach C. Bay D. Island 18. Tom burnt his hand when he _____ the dinner. A. cooked B. was cooking C. has cooked D. cooks 19. Peter: ‘I can’t read this.’- Mary: “You _____ about my handwriting.” A. always complain B. has always complained C. always complained D. are always complaining 20. A cup of tea sounds______. A. perfect B. perfectly C. perfection D. perfectionist
Tính hợp lí : (-58)×23-58×77+100
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