1. Xác định các chất oxi hóa, CK và quá trình oxi hóa khử trong các phương trình sau:
(!). NH3 + O2 ---> NO + H2O
(2) Zn + H2SO4 ---> ZnSO4 + H2S + H2O
(3) Mg + HNO3 ---> Mg(NO3)2 + NH4NO3 + H2O
(4) MnO2 + HCl ---> MnCl2 + Cl2 +H2O
(5) KMnO4 + HCl ---> KCl + MnCl2 + Cl2 + H2O
(6) FeO + HNO3 ---> Fe(NO3)3 + N2O + H2O
(7) KMnO4 + K2SO3 + H2O ---> K2SO4 + MnO2 + KOH
(8) KMnO4 + FeSO4 + H2SO4 ---> Fe2(SO4)3 + MnSO4 + K2SO4 + H2O
(9) KMnO4 ---> K2MnO4 + O2 + MnO2
1. Cho các phản ứng sau:
(1) Fe3O4 + CO ---> FeO + CO2
(2) CH3COOH + C2H5OH ---> CH3COOC2H5 + H2O
(3) HCl + MnO2 ---> MnCl2 + Cl2 + H2O
(4) FeO + HNO3 ---> Fe(NO3)3 + NO + H2O
(5) C6H12O6 ---> C2H5OH + CO2
(6) CH3CH=O + Cu(OH)2 ---> CH3COOH + Cu2O + H2O
Hãy cho biết những phản ứng là phản ứng oxi hóa - khử? vì sao?
1. Xác định số oxi hóa của Nitơ trong các chất và ion sau:N2 , NH3, NO, N2O, NO2HNO3,NH4+, NO3-.
2. Xác định số oxi hóa của lưu huỳnh trong các chất và ion sau: H2S, SO2, SO3, SO32-, H2SO4, HSO4-
3. Xác định số oxi hóa của Mangan trong cái chất và ion sau: MnO4-, MnO2, MnO42-, MnSO4.
4. XÁc định số oxi hóa của Clo trong các chất và ion sau: Cl2, HCl, HClO, KClO3, KClO4.
1. "I practise speaking English every day" Long said
=>Long said that he............................................
2. I'm sorry, I can't help you.
=> I wish I......................
3. I can't do this test because it is difficult
=> If the test were not difficult, I......................
4. lest's go to the cinema
=> What about.................
5. This is the firts time I have used this camera
=> I .........................
6. I haven't seen her for a long time
=> I didn't.............................
7. People live longer. They take physical exercise
=> Peo who take......................
8. "Ican't do this test" Mai said
=> Mai said that..............
9.They will hold a meeting in this hall
=> A meeting...............
10. We always spend 45 minutes doing an english test
=> It alway takes us......................
1. Last summer i (visit) ........... Ha Long Bay with my classmates
2. It (be) ................ often hot in the Summer
3. I like (read) .......... stories. Stories tell about famous people
4. ............. you ever (eat)................... French food? No,I haven't
5. Nam and Ba (play) ............... soccer at the momment
56.Nga enjoys listening to traditional music.
->Nga is fond _________________________________________________.
57."How do you go to school?" Lan asked Mai
->Lan asked Mai_______________________________________________.
58.Let's meet at the cafe corner.
->Bao suggested______________________________________________.
59. I regret not finishing my home work at the weekend
-> I wish I_______________________________________________
60.I have never eaten this kind of food before
-> Its is the first time________________________________
61. I last saw my grandparents two months ago
-> I haven't____________________________
62. The man is my father. he is talking to Mrs. Hoa
-> the man who is __________________________
63. "I Can do this exercise." Bill said
-> Bill said that _______________________
64. You must write these music lessons in link
-> These music lessons ____________________ written in link
65. I don't live in a big city, so I can't go to the cinema very often
-> If I____________________