mk cần gấp ạ Bài tập 4: Trình bày phương pháp hoá học để phân biệt các chất khí không màu (đựng trong các bình riêng biệt mất nhãn): CO, CO 2 , H 2 . Bài tập 5: Cho 10,4 gam hỗn hợp gồm MgO, MgCO 3 hoà tan hoàn toàn trong dung dịch HCl, khí sinh ra được hấp thụ hoàn toàn bằng dung dịch Ca(OH) 2 dư, thấy thu được 10 gam kết tủa. Tính khối lượng mỗi chất trong hỗn hợp ban đầu.

Các câu hỏi liên quan

I. Choose the best answer18. Let’s dance together, ...............................................? A. do we B. don’t we C. shall we D. shan’t we 19. Sit down, ...............................................? A. do you B. don’t you C. will you D. won’t you 20. Nothing makes you bored, ...............................................? A. don’t they B. do they C. doesn’t it D. does it 21. They are not coming, ...............................................? A. are they B. aren’t they C. isn’t it D. doesn’t it 22. The Internet is very fast, ...............................................? A. is it B. isn’t it C. does it D. doesn’t it 23. Every one makes the cakes, ...............................................? A. don’t they B. do they C. are they D. aren’t they 24. Everything is okay, ...............................................? A. is it B. isn’t it C. are they D. aren’t they 25. Nobody called on the phone, ...............................................? A. did he B. didn’t he C. did they D. didn’t they 26. Nothing is wrong, ...............................................? A. is it B. are they C. isn’t it D. aren’t they 27. I’m supposed to be here, ...............................................? A. am I B. am not I C. are I D. aren’t I 28. No one died in the accident, ...............................................? A. is he B. isn’t he C. did they D. didn’t they 29. That’s Bob, ...............................................? A. is he B. is it C. isn’t it D. isn’t he 30. There are more countries north of the equator than south of it, ...............? A. isn’t it B. is it C. aren’t there D. aren’t they 31. They produced the first T.V picture in 1962, .......................................? A. are they B. aren’t they C. do they D. didn’t they 32. You visited your mother last weekend, ...............................................? A. did you B. didn’t you C. do you D. don’t you 33. You love it, ...............................................? A. do you B. don’t you C. are you D. aren’t you 34. Mr Tuan never goes to work late, ...............................................? A. is he B. isn’t he C. does he D. doen’t he 35. He used to sell traditional handicraft, ...............................................? A. hasn’t he B. didn’t he C. doesn’t he D. wasn’t he