Muối CuSO4 có thể phản ứng với dãy chất nào sau đây ? A. CO2, NaOH, H2SO4. B. H2SO4, AgNO3, Cu(OH)2. C. NaOH, BaCl2, Fe, H2SO4. D. NaOH, BaCl2, Fe, Al. Câu 2: Dung dịch Na2SO4 tác dụng được với base nào sau đây? A. Ba(OH)2 B. Cu(OH)2 C. NaOH D. Mg(OH)2 Câu 3: Dãy gồm những cặp chất phản ứng được với nhau là : A. HCl và NaCl ; CO2 và Ca(OH)2 ; Ca(NO3)2 và HCl B. HCl và AgNO3; Na2CO3 và Ca(OH)2; KOH và Cu(NO3)2 C. HCl và Cu(NO3)2; NaCl và Ca(NO3)2; KOH và Cu(NO3)2 D. HCl và NaCl; NaCl và Ca(NO3)2; KOH và Cu(NO3)2 Câu 4: Khi trộn hai dung dịch của các cặp chất sau, trường hợp nào xảy ra phản ứng? A. Dung dịch BaCl2 và dung dịch CuSO4. B. dung dịch Ca(NO3)2 và dung dịch NaCl C. Dung dịch K2SO4 và dung dịch MgCl2 D. dung dịch CuCl2 và dung dịch FeSO4. Bài 1: Cho các chất : CaCO3, HCl, NaOH, CuCl2, BaCl2, K2SO4. Có bao nhiêu cặp chất có thể phản ứng với nhau ? Viết các PTHH (nếu có). Giúp mình với ạ , cần gấp lắm luôn

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1/D

2/A

3/B

4/C

 

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Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions. It is often considered that the schoolyard is where bullies go to make other kids a miserable school life, but a new study suggests that classrooms are another popular place. The study, presented recently at the American Public Health Association's yearly meeting in Philadelphia, is based on the results of the research from more than 10,000 middle school students who answered questions online. Of those researched, 43% said they'd been physically bullied within the last month. A bit more than half said they had been laughed at in an unfriendly way, and half reported being called hurtful names. About one third said groups had excluded them to hurt their feelings. 28% said their belongings had been taken or broken; 21% said someone had threatened to hurt them. According to the results, two-thirds of the students said they had been bullied in more than one way over the previous month. The study authors mentioned that 8% of the students who answered said they had missed school at least once during the school year because of fear of being bullied. 25% said they had taken other actions, such as missing recess, not going to the bathroom or lunch, missing classes, or staying away from some area of the school to escape from experiencing a bully. Bullies did too much to the school life. 28. Bullies can happen in the following places EXCEPT_______. A. schoolyards B. classrooms C. bathrooms D. teachers' offices 29. The underlined phrase ‘‘laughed at” in the passage is closest in meaning to_______ A. made fun of B. smiled nicely C. shouted at D. looked after well 30. Which of the following might some students do to protect themselves from bullies? A. They miss school. B. They call their parents for help, C. They try to hurt others. D. They break others' belongings. 31. How does the writer feel about bullies at school? A. Excited B. Disappointed C. Worried D. Puzzled 32. Which of the following is probably the best title for the passage? A. Bad School Life B. Bullies at School C. Fear at School D. School Problems

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