Câu 1.
Mg + 2HCl ==> MgCl2 + H2
0,05............................................0,05 (mol)
Fe + 2HCl ==> FeCl2 + H2
0,05.......................................0,05...(mol)
Ta có: nMg= 1,2/24= 0,05 (mol)
nFe= 2,8/56= 0,05 (mol)
==> nH2= 0,05 + 0,05= 0,1 (mol)
==> VH2= 0,1x22,4= 2,24 (l)
Câu 2.
a) 2Fe + 3Cl2 =nhiệt độ==> 2FeCl3
b) SiO2 + 4HF ==> SiF4 + 2H2O
c) 2KMnO4 + 16HCl ==> 2KCl + 2MnCl2 + 5Cl2 + 8H2O
d) Cl2 + 2NaBr ==> 2NaCl + Br2
Câu 3.
FeS2 + O2 ==> SO2 + Fe2O3
SO2 + H2S ==> S + H2O
S + H2 ==> H2S
H2S + O2 ==> H2O + S
S + Fe == FeS
FeS + HCl => FeCl2 + H2S
H2S + H2O + Cl2 ==> H2SO4 + HCl
H2SO4 + CuO ==>CuSO4 + H2O
CuSO4 + H2S ==> CuS + H2SO4
H2SO4 + S ===> SO2 + H2O
SO2 + KOH ==> K2SO3 + H2O
K2SO3 + H2SO4 ==> K2SO4 + SO2 + H2O
P/s: Bạn tự cân bằng giúp mình nhé