$(1) 2Al_2O_3 \xrightarrow{đpnc} 4Al + 3O_2$
$2Al + 6HCl \to 2AlCl_3 + 3H_2$
$AlCl_3 + 3KOH \to Al(OH)_3 + 3KCl$
$(2) Fe_2O_3 + 3CO \xrightarrow{t^o} 2Fe + 3CO_2$
$2Fe  + 3Cl_2 \xrightarrow{t^o} 2FeCl_3$
$FeCl_3 + 3KOH \to Fe(OH)_3 + 3KCl$
$(3) 2Fe  + 3Cl_2 \xrightarrow{t^o} 2FeCl_3$
$FeCl_3 + 3KOH \to Fe(OH)_3 + 3KCl$
$2Fe(OH)_3 \xrightarrow{t^o} Fe_2O_3 + 3H_2O$
$Fe_2O_3 + 3CO \xrightarrow{t^o} 2Fe + 3CO_2$
$Fe + 6H_2SO_4 \to Fe_2(SO_4)_3 + 3SO_2 + 6H_2O$

a) SO₂ + Na₂O -> Na₂SO₃

Na₂SO₃ + H₂SO₄ -> Na₂SO₄ + SO₂ + H₂O

Na₂SO₄ + Ba(OH)₂ -> BaSO₄ \(\downarrow\)+ 2NaOH

2NaOH + CO₂ -> Na₂CO₃ + H₂O

b) CaO + CO₂ -> CaCO₃

CaCO₃ \(\rightarrow^{t^o}\) CaO + CO₂

CaO + H₂O -> Ca ( OH)₂

Ca ( OH)₂ + CO₂ -> CaCO₃ + H₂O

CaCO₃ + H₂SO₄ -> CaSO₄ + CO₂ + H₂O

c) 2Fe + 3Cl₂ \(\rightarrow^{t^o}\) 2FeCl₃

FeCl₃ + 3NaOH -> Fe(OH)₃ \(\downarrow\) + 3NaCl

2Fe(OH)₃ \(\rightarrow^{t^o}\) Fe₂O₃ + 3H₂O

Fe₂O₃ + 3H₂SO₄ -> Fe₂(SO₄)₃ + 3H₂O

Fe₂(SO₄)₃ + 3BaCl₂ -> 2FeCl₃ + 3BaSO₄\(\downarrow\)

d) Fe + 2HCl -> FeCl₂ + H₂

FeCl₂ + 2AgNO₃ -> 2AgCl\(\downarrow\) + Fe(NO₃)₂

Fe(NO₃)₂ + 2NaOH -> Fe(OH)₂\(\downarrow\) + 2NaNO₃

Fe(OH)₂ + H₂SO₄ -> FeSO₄ + 2H₂O

a, SO₂ + 2NaOH \(\rightarrow\)Na₂SO₃ + H₂O

Na₂SO₃ + H₂SO₄ \(\rightarrow\)Na₂SO₄ + H₂O + SO₂

Na₂SO₄ + Ba(OH)₂\(\rightarrow\) BaSO₄+ 2 NaOH

CO₂ + 2 NaOH \(\rightarrow\)Na₂CO₃ + H₂O

b, CaO + CO₂\(\rightarrow\) CaCO₃

CaCO₃ -t⁰-> CaO + CO₂

CaO + H₂O \(\rightarrow\)Ca(OH)₂

Ca(OH)₂ + CO₂ \(\rightarrow\)CaCO₃ + H₂O

CaCO₃ + H₂SO₄ \(\rightarrow\)CaSO₄ + H₂O + CO₂

c, 2Fe + 3Cl₂ -t⁰-> 2FeCl₃

FeCl₃ + 3NaOH \(\rightarrow\)Fe(OH)₃ + 3NaCl

2Fe(OH)₃ -t⁰-> Fe₂O₃ + 3H₂O

Fe₂O₃ + 3H₂SO₄ \(\rightarrow\)Fe₂(SO4)₃ + 3H₂O

Fe₂(SO4)₃ + 3BaCl₂ \(\rightarrow\)2FeCl₃ + 3BaSO₄

d, Fe + 2HCl \(\rightarrow\)FeCl₂ + H₂

FeCl_{2 +} 2AgNO₃ \(\rightarrow\)Fe(NO₃)₂ + 2AgCl

Fe(NO₃)₂ + 2NaOH \(\rightarrow\)Fe(OH)₂ + 2NaNO₃

Fe(OH)₂ + H₂SO₄\(\rightarrow\) FeSO₄ + 2H₂O

e, 2Cu + O₂ -t⁰-> 2CuO

CuO + 2HCl \(\rightarrow\)CuCl₂ + H₂O

CuCl₂ + 2NaOH\(\rightarrow\) Cu(OH)₂ + 2NaCl

Cu(OH)₂ -t⁰-> CuO + H₂O

CuO + H₂ -t⁰-> Cu + H₂O

Cu + 2H₂SO_4đặc \(\rightarrow\)CuSO₄ + SO₂ + 2H₂O

f, 2Al₂O₃ -đpnc/ criolit-> 4Al + 3O₂

2Al + 3Cl₂ -t⁰-> 2AlCl₃

AlCl₃ + 3NaOH \(\rightarrow\)Al(OH)₃ + 3NaCl

2NaCl + 2H₂O -đpmn-> 2NaOH + Cl₂ + H₂

2NaOH + CuCl₂ \(\rightarrow\)Cu(OH)₂ + 2NaCl

$C + O_2 \xrightarrow{t^o} CO_2$
$CO_2 + Ca(OH)_2 \to CaCO_3 + H_2O$
$CaCO_3 + 2HCl \to CaCl_2 + CO_2 + H_2O$
$CO_2 + C \to 2CO$

$C_2H_4 + H_2O \xrightarrow{t^o,H^+} C_2H_5OH$
$C_2H_5OH + O_2 \xrightarrow{men\ giấm} CH_3COOH + H_2O$
$CH_3COOH + C_2H_5OH \buildrel{{H_2SO_4,t^o}}\over\rightleftharpoons CH_3COOC_2H_5 + H_2O$
$CH_3COOC_2H_5 + NaOH \to CH_3COONa + C_2H_5OH$

3Fe+2O₂ \(\underrightarrow{t^o}\) Fe3O4 (1)

\(a) P_2O_5 + 3H_2O \to 2H_3PO_4\\ b) Fe_2O_3 + 3H_2 \xrightarrow{t^o} 2F e+ 3H_2O\\ c) Mg + 2HCl \to MgCl_2 + H_2\\d) 2KClO_3 \xrightarrow{t^o} 2KCl + 3O_2\\ e) 2K + 2H_2O \to 2KOH + H_2\\ f) CH_4 + 2O_2 \xrightarrow{t^o} CO_2 + 2H_2O\)

\(a) 4P + 5O_2 \xrightarrow{t^o} 2P_2O_5\\ P_2O_5 + 3H_2O \to 2H_3PO_4\\ b) 2KClO_3 \xrightarrow{t^o} 2KCl + 3O_2\\ S + O_2 \xrightarrow{t^o} SO_2\\ SO_2 + H_2O \to H_2SO_3\\ 2Ca + O_2 \xrightarrow{t^o} 2CaO\\ CaO + H_2O \to Ca(OH)_2\\ Ca(OH)_2 + CO_2 \to CaCO_3 + H_2O\)

a)\(4FeS_2+11O_2\underrightarrow{t^o}2Fe_2O_3+8SO_2\)

\(2SO_2+O_2\underrightarrow{t^o}2SO_3\)

\(SO_3+H_2O\rightarrow H_2SO_4\)

b)\(m_{H_2SO_4}=\dfrac{50\cdot49\%}{100\%}=24,5g\Rightarrow n_{H_2SO_4}=0,25mol\)

Từ quá trình trên: \(4FeS_2\rightarrow H_2SO_4\)

\(\Rightarrow n_{FeS_2}=\dfrac{1}{4}n_{H_2SO_4}=\dfrac{1}{4}\cdot0,25=\dfrac{1}{16}mol\)\

\(m_{FeS_2}=\dfrac{1}{16}\cdot120=7,5g\)

c)\(n_{NaOH}=0,3\cdot1=0,3mol\)

\(SO_2+2NaOH\rightarrow Na_2SO_3+H_2O\)

0,15       0,3                 0,15

\(m_{Na_2SO_3}=0,15\cdot126=18,9g\)

CH4 + 2O2 -> (t°) CO2 + 2H2O

C2H2 + 2Br2 -> C2H2Br4

CH4 + Cl2 -> (askt) CH3Cl + HCl

2C2H2 + 5O2 -> (t°) 4CO2 + 2H2O

C2H4 + Br2 -> C2H4Br2

nCH2=CH2 -> (t°, p, xt) n(-CH2-CH2-)

C2H4 + 3O2 -> (t°) 2CO2 + 2H2O