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Important Chemical Reactions

Halogenation by Electrophilic Addition Reactions in Alkenes

Single and Double Replacement Reactions and Net Ionic Reactions

How to Draw Lewis Dot Structure

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Important Chemical Reactions

(1) Sulphur Sulphuric acid


2SO2+O2 2SO3

SO3+ H2O H2SO4

(2) Calcium Calcium Hydroxide

2Ca +O2 2CaO


(3) Nitrogen Nitric Acid (HNO3) + Nitrous Acid (HNO2)

N2+O2 2NO

2NO +O 22NO2


(4) Nitrogen Ammonium Hydroxide


N2+3H2 2NH3


(5)Sodium Sodium Hydroxide


2Na + 2H2O 2NaOH +H2

or 4Na +O2 2Na2O

Na2O+H2O 2 NaOH

(6) Iron Ferric Hydroxide

Fe Fe(OH) 3

2Fe+3Cl 2 2FeCl 3

FeCl3+3H2OFe(OH)3+ 3HCl

(7) Iron Ferrous Hydroxide

Fe + 2HCl(cold and dilute) FeCl2

FeCl2+2H2OFe(OH)2+ 2HCl

(8) Copper Copper Sulfate

Cu + Conc H2SO4 CuSO4 + 2H2O + SO2

Chemical reaction to distinguish between Mixture and Comound

Fe +S+2HCl FeCl2+S+H2(blue flame pop sound)

FeS+2HClFeCl2 +H2S( rotten smell gas )

Important reactions for the preparation of Oxygen (O2)

Decomposition reactions

Decomposition of red Mercuric oxide

2HgO 2Hg+O2

Decomposition of hydrogen peroxide

2H2O2 H2+O2

Decomposition of potassium chlorate

2KClO3 2KCl +3O2

Decomposition of silver(I) oxide

2Ag 2O 4Ag+O2

Decomposition of lead oxide

2Pb 3O4 6PbO 2

Red Litharge

2PbO2 2PbO+O 2

Combustion reactions

CxH2y + (x+y/2)O2xCO2+yH2O

(easy way of balancing a combustion reaction of hydrocarbons )

CH4 +2O2 CO2 +2H2O


C2H6 + 7/2O2 2CO2 +3H2O


C10H20 + 15O2 10CO2 +10H2O


C6H14 + 19/2O2 6CO2 +7H2O


C2H2+5/2O2 2CO2+H2O


Oxidation of Iron or combustion of iron

4Fe+3O2 2Fe2O3

Oxidation of glucose or burning of food

C6H12O6 + 6O2 6CO2 +6H2O + heat

Reaction of oxygen with nitric oxide

2NO+O2 2NO2

Reaction of Magnesium to form magnesium oxide

2Mg + O2 2MgO

Formation of Sulfur trioxide or combustion of sulfur trioxide

2SO 2+O2 2SO3

Oxidation of Ammonia

4NH 3+ 3O 2 2NO2 + 6H2O

Oxidation of Aluminium

4Al +3O2 2Al2O3(white)

Combustion or oxidation of H2S

2H2S+3O2 2SO2+2H2O

Oxidation of Zinc

2Zn +O2 2ZnO (Yellow when hot white cold)

Oxidation of Carbon disulfide

CS2+3O2 CO2+2SO2

Oxidation of lead

Pb+O2 2PbO (Yellow)

Oxidation of Zinc sulfide

2ZnS+3O2 2ZnO+2SO2

Oxidation of copper

Cu+O2 2CuO (black)

Oxidation of mercury

2Hg +O2 2HgO (red)

C2H2OH 7O2

Catalytic nature of water

4Fe + 3O2 2Fe2O3

H2OH2 +1/2 O2

4P + 5SO2 2P2O5 + 5S


Example of hydrated Compounds with Common names and Formulae

Barium chloride dihydrate BaCl2 .2H2O

Calcium sulphate dihydrate or Gypsum CaSO2.2H2O

Copper nitrate trihydrate Cu(NO3)2.3H2O

Copper II chloride tetrahydrate CuCl2.4H2O

Copper II sulphate pentrahydrate or Blue vitriol CuSO2.5H2O

Calcium chloride hexahydrate or CaCl2.6H2O

Iron (II) sulphate heptahydrate or Green vitriol FeSO4.7H2 O

Zinc sulphate heptahydrate or White vitriol ZnSO4.7H4O

Magnesium sulphate heptahydrate or Epsom salt MgSO4.7H2O

Sodium carbonate decahydrote or Washing soda Na2CO3.10H2O

Sodium sulphate decahydrate or Glauber’s salt Na2SO4.10H2O

Efflorescence —- When exposed to air lose their water of crystallization and transformed to powder substance .for example Na2CO3.10H2O

Deliquescent crystals —-When exposed to air lose their water of crystallization and transformed to saturated solutions.

For example CuSO4.5H2O ,when exposed to air at ordinary temperature it absorbs water from air and becomes a saturated solution.

CaCl2,6H2O, MgCl2. 6H2O , NaOH, KOH, ZnCl2, Zn (NO3)2,Cu(NO3)2

Hygroscopic Substances absorb moisture without dissolving in water

CaCl2 , MgCl2 , H2SO4,CaO, P2O2, CuO ,silica gel alcohol.

List of some Important Solvents

• S in Carbon DiSulfide CS2

• Paraffin wax in turpentine

• Rubber in benzene

• Iodine in Ethylalcohol

• Paint in turpentine

• Niter in water

• Nail Polish in Acetone

• Rust in oxlalic acid

• Chlorophyll in Methylated sprint

• Oil in Petrol

Flame tests :

As Arsenic Blue

B Boron Bright green

Ba Barium Pale/Apple green

Ca Calcium Brick red

Cs Caesium Blue – [Violet (color)Violet]

Cu(I) Copper(I) Blue

Cu(II) Copper(II) (non-halide) Green

Cu(II) Copper(II) (halide) Blue-green

Fe Iron Gold

In Indium Blue

K Potassium [[Lilac (colour)|Lilac](violet]

Li Lithium Pink-Red

Mg Magnesium Bright white

Mo Molybdenum Yellowish green

Na Sodium Intense yellow

P Phosphorus Pale bluish green

Pb Lead Blue

Rb Rubidium Red-violet

Sb Antimony Pale green

Se Selenium Azure blue

Sr Strontium Red

Te Tellurium Pale green

Tl Thallium Pure green

Zn Zinc Bluish green

Copper Compound Lithium Compound Potassium Compound Sodium Compound