Lead Acetate
source :scbt
Method of Preparation :
By the reaction of litharge and acetic acid : Lead acetate solution is obtained which on concentration gives crystal of (CH3COO)2Pb.3H2O
Properties of lead acetate:
1. It is colorless crystalline solid, soluble in water. Its aqueous solution is sweet but poisonous.
2. Effect of heat : we get acetone .
3. Reaction with H2S : Black precipitate of lead acetate is obtained.
4. Reaction with HCl : As a result we get white precipitate of lead chloride.
5. Reaction with Potassium chromate ( K2CrO4) : yellow precipitate of Lead chromate is formed.
6. Reaction with Sodium bicarbonate (NaHCO3) : white precipitate of lead carbonate is formed.
7. Reaction with litharge : Basic lead acetate is obtained.
Uses :
- As medicines in curing skin disease.
- In the preparation of basic lead acetate.
Method of preparation: by the reaction of lead acetate with litharge
Properties of basic lead acetate:
1. It is colorless crystalline solid soluble in water.
2. Reaction with CO2: white precipitate is obtained.
Uses:
- In the preparation of white lead.
- In medicines.
Red lead (Pb3O4) Triplumbic tetra oxide, Sindoor
Method of preparation :
By heating litharge with air : At 340 degree red lead is obtained.
6Pbo + O2 ———> 2Pb3O4
[Note: Red lead is a mixture of PbO2 + 2PbO]
Properties :
i) It is red powder, insoluble in water.
ii) Effect of heat : It decomposes at 470 degree
2Pb3O4 ———–> 6PbO + O2
iii) Reaction with dilute HNO3 : As a result of reaction we get Lead nitrate and lead dioxide .
Pb3O4 + 2HNO3 ———–> Pb(NO3)2 + 2PbO2 + H2O
iv) Reaction with concentrated HCl : We get lead chloride and chlorine .
Pb3O4 + 8HCl ———-> 3 PbCl2 + Cl2 + 4H2O
Uses :
i) As a red pigment
ii) In the protection of iron from rusting.
Conversion Questions:
a) Tin to anhydrous stannous chloride :
b) stannous chloride ( SnCl2) to Tin :
c) Litharge to red lead :
d) Red lead to litharge :
e) Lead to lead nitrate :
f) Lead nitrate to white lead :
6 Pb(NO3)2 + 6Na2CO3 + 2H2O ——–> 2[2PbCO3 . Pb(OH)2] +12NaNO3+ 2CO2
