CH1 CHEMICAL REACTIONS AND EQUATIONS - ALL EQUATIONS

2Mg + O2

2MgO

Zn + H2SO4 →

ZnSO4 + H2

3Fe (s)+ 4H2O (g) →

Fe3O4 (s)+ 4H2 (g)

CO (g) + 2H2 (g) ——340 atm→

CH3OH (l)

6 CO2 (aq) + 12 H2O (l) —sunlight & chlorophyll→

C6H12O6 (aq) + 6O2 (aq) + 6H2O (l)

names for CaO

• calcium oxide

• quick lime

CaO(s) + H2O (l) →

Ca(OH)2(aq) + heat

names for Ca(OH)2

• calcium hydroxide

• slaked lime

Ca(OH)2 (aq) + CO2 (g) →

CaCO3 (s) + H2O (l)

names/uses of CaCO3

calcium carbonate, used for whitewashing,

also called marble

C + O2 →

CO2

2H2 (g) + O2 (g) →

2H2O (l)

all combination reactions are _____________.

exothermic

exception: formation of nitrogen monoxide from nitrogen and oxygen (N₂ + O₂ → 2NO)

all decomposition reactions are_____________.

endothermic

exception: decomposition of hydrogen peroxide (2H₂O₂ → 2H₂O + O₂)

Is dilution and dissolution exothermic or endothermic? mention an exception.

generally exothermic

exception: Dilution of Ammonium Nitrate (NH₄NO₃) in Water

NH₄NO₃(s) → NH₄⁺(aq) + NO₃⁻(aq)

3 exothermic reactions

1. CH4(g) + 2O2 (g)→ CO2(g) + 2H2O(g)

2. C6H12O6 (aq) + 6 O2 (aq) → 6 CO2 (aq) + 6 H2O (l) + ATP

3. decomposition of vegetable matter

3 examples of thermal decomposition

1. 2 FeSO4(s) —heat→ Fe2O3(s) + SO2(g) + SO3(g)

   [green ferrous sulphate turns into reddish brown ferric oxide]

2. CaCO3 (s) —heat→ CaO (s) + CO2 (g)

   [CaO used in manufacture of cement]

3. 2 Pb(NO3)2 (g) —heat→ 2PbO (s) + 4NO2 (g) + O2 (g)

   [PbO is yellow solid, NO2 is brown gas]

example of electrolytic decomposition

2H2O —electricity→ 2H2 + O2

examples of photolytic decomposition

1. 2AgCl (s) —sunlight→ 2Ag(s) + Cl2(g)

2. 2AgBr (s) —sunlight→ 2Ag(s) + Br2 (g)

these reactions are used in black and white photography

examples of single displacement

1. Fe(s) + CuSO4 (aq) → FeSO4 (aq) + Cu(s)

2. Zn(s) + CuSO4 (aq) → ZnSO4 (aq) + Cu(s)

3. Pb(s) + CuCl2 (aq) → PbCl2 (aq) + Cu(s)

give an example for a double displacement reaction

Na2SO4 (aq) + BaCl2 (aq) → BaSO4 (s) + 2NaCl(aq)
[white precipitate - BaSO4 is formed]

since precipitate is formed, this is also a precipitation reaction

give an example of oxidation reaction [gain O2, lose H2]

2Cu + O2 —heat→ 2CuO

here copper gets oxidized by gaining O2

give an example of reduction reaction [lose O2, gain H2]

H2​+S→H2​S

here sulfur gets reduced by gaining H2

give examples of redox reactions [oxidation + reduction]

1. CuO + H2 —heat→ Cu + H2O

   [Cu gets reduced, H2 gets oxidised]

2. ZnO + C → Zn + CO

   [Zn is reduced, C is oxidised]

3. MnO2 + 4HCl → MnCl2 + 2H2O + Cl2

   [MnO2 is reduced, HCl is oxidised]