Important Chemical Reactions

(1) Sulphur Sulphuric acid

S+O₂SO₂

2SO₂+O₂ 2SO₃

SO₃+ H₂O H₂SO₄

(2) Calcium Calcium Hydroxide

2Ca +O₂ 2CaO

CaO+H₂OCa(OH)₂

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

N₂+O₂ 2NO

2NO +O ₂2NO₂

2NO₂+H₂O HNO₂+HNO₃

(4) Nitrogen Ammonium Hydroxide

N₂ NH₄OH

N₂+3H₂ 2NH₃

NH₃+H₂ONH₄OH

(5)Sodium Sodium Hydroxide

Na NaOH

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

methane

C₂H₆ + 7/2O₂ 2CO₂ +3H₂O

ethane

C₁₀H₂₀ + 15O₂ 10CO₂ +10H₂O

decene

C₆H₁₄ + 19/2O₂ 6CO₂ +7H₂O

hexane

C₂H₂+5/2O₂ 2CO₂+H₂O

ethene

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 CuSO_4.5H₂O ,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