$a)  CaO + H_2O \to Ca(OH)_2$
$b) NaOH + HCl \to NaCl + H_2O$
$c) Ca(OH)_2 + 2HNO_3 \to Ca(NO_3)_2 + 2H_2O$
$d) AlCl_3 + 3NaOH \to Al(OH)_3 + 3NaCl$
$e) Mg(NO_3)_2 + Ca(OH)_2 \to Ca(NO_3)_2 + Mg(OH)_2$
$f) CuCl_2 + 2KOH \to Cu(OH)_2 + 2KCl$

$g) Fe(OH)_2 + H_2SO_4 \to FeSO_4 + 2H_2O$
$h) 2Fe(OH)_3 + 3H_2SO_4 \to Fe_2(SO_4)_3 + 6H_2O$
$i) Al_2(SO_4)_3 + 3BaCl_2 \to 3BaSO_4 + 2AlCl_3$

a) 3Fe +2 O₂ --t^o--> Fe₃O₄

b) 4P + 5O₂ --t^o--> 2P₂O₅

c) Al₂O₃ + 3H₂SO₄ --> Al₂(SO₄)₃ + 3H₂O

d) Fe₂O₃ + 3H₂SO₄ --> Fe₂(SO₄)₃ + 3H₂O

e) 2Cu(NO₃)₂ --t^o--> 2CuO + 4NO₂ + O₂

\(a,3Fe+2O_2\xrightarrow{t^o}Fe_3O_4\\ b,4P+5O_2\xrightarrow{t^o}2P_2O_5\\ c,Al_2O_3+3H_2SO_4\to Al_2(SO_4)_3+3H_2O\\ d,Fe_2O_3+3H_2SO_4\to Fe_2(SO_4)_3+3H_2O\\ e,2Cu(NO_3)_2\xrightarrow{t^o}2CuO+4NO_2+O_2\uparrow\)

\(Fe+2HCl\rightarrow FeCl_2+H_2\)

\(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

\(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\)

\(2Al\left(OH\right)_3+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+6H_2O\)

\(CuO+2HNO_3\rightarrow Cu\left(NO_3\right)_2+H_2O\)

 1. Fe + 2HCl → FeCl2 + H2

2Al + 3H2SO4 → Al2(SO4)3 + 3H2

CuO + H2SO4 → CuSO4 + H2O

2Al(OH)3 + 3H2SO4 → Al2(SO4)3 + 6H2O

CuO + 2HNO3 → Cu(NO3)2 + H2O

Chọn D

\(PTK_{Mg\left(OH\right)_2}=24+\left(16+1\right).2=58\left(đvC\right)\)

\(PTK_{Ca\left(H_2PO_4\right)_2}=40+\left(1.2+31+16.4\right).2=234\left(đvC\right)\)

\(PTK_{Ba_3\left(PO_4\right)_2}=137.3+\left(31+16.4\right).2=601\left(đvC\right)\)

\(PTK_{Al_2\left(SO_4\right)_3}=27.2+\left(32+16.4\right).3=342\left(đvC\right)\)

\(PTK_{Ca\left(HCO_3\right)_2}=40+\left(1+12+16.3\right).2=162\left(đvC\right)\)

\(PTK_{Fe\left(NO_3\right)_2}=56+\left(14+16.3\right).2=180\left(đvC\right)\)

\(PTK_{Mg\left(OH\right)_2}=24+\left(16+1\right)\cdot2=58\left(đvC\right)\\ PTK_{Ca\left(H_2PO_4\right)_2}=40+\left(2+31+16\cdot4\right)\cdot2=234\left(đvC\right)\\ PTK_{Ba_3\left(PO_4\right)_2}=137\cdot3+\left(31+16\cdot4\right)\cdot2=601\left(đvC\right)\\ PTK_{Al_2\left(SO_4\right)_3}=27\cdot2+\left(32+16\cdot4\right)\cdot3=342\left(đvC\right)\\ PTK_{Ca\left(HCO_3\right)_2}=40+\left(1+12+16\cdot3\right)\cdot2=162\left(đvC\right)\\ PTK_{Fe\left(NO_3\right)_2}=56+\left(14+16\cdot3\right)\cdot2=180\left(đvC\right)\)

3Cu+ 8HNO3-->  3Cu(NO3)2+ 2NO+ 4H2O
Cu+ 4HNO3-->Cu(NO3)2+2NO2+ 2H2O
2Fe+ 6H2SO4-->Fe2(SO4)3+ 3SO2+ 6H20
2Al+ 6H2SO4--> Al2(SO4)3+ 3SO2+ 6H2O
6Al+ 12H2SO4--> 3Al2(SO4)3+3S+ 12H2O
3Al+ 12HNO3--> 3Al(NO3)3+ 3NO+ 6H2O
10Al+ 32HNO3--> 10Al(NO3)3+ N2+ 16H2O
8Al+ 30HNO3--> 8Al(NO3)3+ 3NH4NO3+ 9H2O
 

1.2FeO  +     \(\dfrac{1}{2}\)O₂  →  Fe₂O₃

2.2Fe_xO­_y   +   \(\dfrac{3x-2y}{2}\)   O₂  →  xFe₂O₃

3.2Al +     6HCl  → 2AlCl₃ +       3H₂

4.Al₂O₃  +  3H₂SO₄  →  Al₂(SO₄)₃  +  3H₂O

5.Al(OH)₃   +     3HNO₃  →  Al(NO₃)₃   +       3H₂O

6. 2Al +             3H₂SO₄  →  Al₂(SO₄)₃ +         3H₂

7.2C4H10 + 13O2 → 8CO2 + 10H2O

8. 2KMnO₄  →  K₂MnO₄ +      MnO₂  +     O₂

9.2Cu(NO3)2 → 2CuO + 4NO2 + O2

10.M₂O_x    +        2xHNO₃  →  2M(NO₃)_x   +      xH₂O

11.Mg(OH)₂ +       2HNO₃  →  Mg(NO₃)₂ +     2H₂O

12.KClO₃  →  KCl   +   \(\dfrac{3}{2}\)O₂ 

13.CH4 + 2O2 → CO2 + 2H2O

14.xFe2O3 + (3x-2y)H2 → 2FexOy + (3x-2y)H2O

15.Fe₃O₄   +         8HCl  →  FeCl₂   +       2FeCl₃   +        4H₂O

\(M_{Cl_2}=35.5\cdot2=71\left(đvc\right)\)

\(M_{H_2SO_4}=2\cdot1+32+64=98\left(đvc\right)\)

\(M_{Cu\left(NO_3\right)_2}=64+62\cdot2=188\left(đvc\right)\)

\(M_{Al_2\left(SO_4\right)_3}=27\cdot2+\left(32+16\cdot4\right)\cdot3=342\left(đvc\right)\)