Hoàn thành các PTHH sau:

1. FeCO3+ H2SO4 ----> Fe2(SO4)3 + S + CO2 + H2O

2. Fe3O4+ HNO3 ---> Fe(NO3)3+ N2O+ H2O

3. Al +HNO3 ----> Al(NO3)3+ N2O+ H2O

Al + HNO3 ---> Al(NO3)3 + NH4NO3 + H2O

Mg + H2SO4 ---> MgSO4 + H2S + H2O

Fe + H2SO4 ---> Fe2(SO4)3 + SO2+H2O

Mg + HNO3 ---> Mg(NO3)2 + NO + H2O

C3H8 + HNO3 ---> CO2 + NO+H2O

Cân bằng các PTHH sau

1. CnH2n+ 2+ O2 --->CO2+H2O

2. CnH2n- 2 +O2 ---> CO2 + H2O

3.CnH2n - 6 +O2 ---> Co2+H20

4. CnH2n + 2O + O2 --->CO2+ H2O

1.I think this hobby does not cost you much, and ............ you need is time

A. most B. all C. some D. all of

2. My family enjoys............. because we can sell vegetables and flowers....... money

A. garden- to B . gardening-- for C. gardening-- with D. garden -- of

Put the following sentences into the opposite voice (active or passive)

1. The medals were presented by Nelson Mandela

2. You shouldn't expect your friends to help you