Hòa tan hoàn toàn 2,7 gam kim loại Aluminum Al bằng một lượng vừa đủ dung dịch hydrochloric acid HCl 14,6% thu được V lit khí hydrogen (đkc). a. Tính V. b. Tính khối lượng dung dịch HCl 14,6% cần dùng. c. Tính nồng độ phần trăm của dung dịch muối sau phản ứng.
mạch điện như hình 3 , trong đó R1 = 10Ω, R2 = 20Ω, nguồn điện có hiệu điện thế U = 15V. a.Tính điện trở tương đương của đoạn mạch? b.Tìm số chỉ của ampe kế và của các vôn kế? Cho mạch điện như hình 4, trong đó R1 = 20Ω, R2 = 60Ω, nguồn điện có hiệu điện thế U = 25V a. Tính điện trở tương đương của đoạn mạch? b. Tìm số chỉ của vôn kế và của các ampe kế?
1. I don’t have a car. ->_____________________________ 2. I can’t play the piano.-> ________________________ 3. I don’t have new shoes.->________________________ 4. I can’t go on holiday. ->_________________________ 5. I don’t have time to read lots of books.->__________________ 6. I can’t drive.->_______________________
1. He lives far from the sea. He wishes he … near the sea. A. lives B. lived C. had lived D. would live 2. It’s cold today. I wish it … warmer. A. is B. has been C. were D. had been 3. I wish I … the answer, but I don’t. A. know B. Knew C. had known D. would know 4. She wishes she … blue eyes. A. has B. had C. had had D. would have 5. She wishes she … a movie star one day. A. is B. were C. will be D. would be 6. I have to work on Sunday. I wish I … have to work on Sunday. A. don’t B. didn’t C. won’t D. wouldn’t 7. I wish you … borrow my things without permission. A. don’t B. won’t C. shouldn’t D. wouldn’t 8. He can’t buy a new car. He wishes he … buy a new one. A. could B. had to C. should D. would 9. Nam wishes his father………here to help him now. a/ is b/ were c/ will be d/ was 10. I wish I … help you, but I can’t A. can B. could C. will D. would 1. He lives far from the sea. He wishes he … near the sea. A. lives B. lived C. had lived D. would live 2. It’s cold today. I wish it … warmer. A. is B. has been C. were D. had been 3. I wish I … the answer, but I don’t. A. know B. Knew C. had known D. would know 4. She wishes she … blue eyes. A. has B. had C. had had D. would have 5. She wishes she … a movie star one day. A. is B. were C. will be D. would be 6. I have to work on Sunday. I wish I … have to work on Sunday. A. don’t B. didn’t C. won’t D. wouldn’t 7. I wish you … borrow my things without permission. A. don’t B. won’t C. shouldn’t D. wouldn’t 8. He can’t buy a new car. He wishes he … buy a new one. A. could B. had to C. should D. would 9. Nam wishes his father………here to help him now. a/ is b/ were c/ will be d/ was 10. I wish I … help you, but I can’t A. can B. could C. will D. would
Định luật Ohm Cho mạch điện gồm 2 điện trở R1 = 24 Ω và R2 = 72 Ω mắc nối tiếp vào hiệu điện thế không đổi UAB=24V. a. Tính điện trở tương đương của đoạn mạch AB? b. Tính cường độ dòng điện chạy qua mỗi điện trở? c. Tìm hiệu điện thế giữa hai đầu mỗi điện trở