It is made in the forms of stannous chloride and DihydrateStannous Chloride.
Preparation of Stannous Chloride
Anhydrous stannous chloride is obtained when the dry hydrochloride acid gas flows in the hot tin.
Sn (s) + 2HCl (aq) → SnCl2 (aq) + H2 (g)
Stannous chloride is obtained by heating the tin with mercuric chloride.
Sn + HgCl2→ Hg + SnCl2
Anhydrous stannous chloride cannot be obtained by heating the hydrous stannous chloride(SnCl2.2H2O), as tin oxidechloride is formed upon heating.
SnCl2.2H2O → HCl + Sn(OH)Cl + H2O
Crystals of stannous chloride are obtained by evaporating the solution obtained by heating the tin with concentrated hydrochloride acid.
Sn + 2HCl + 2H2O → SnCl2.2H2O + H2
Stannous chloride solution is also obtained by heating stannous oxide or stannous hydroxide with concentrated hydrochloric acid. Crystals are obtained by evaporation.
SnO + 2HCl + H2O → SnCl2.2H2O
Sn(OH)2 + 2HCl → SnCl2.2H2O
Physical Properties
It is a transparent material like glass. It dissolves in water, ether, and alcohol.
Chemical Properties
Reaction with water: It hydrolysed in excess of water to form tin oxychloride.
SnCl2 (aq) + H2O (l) ⇌ Sn(OH)Cl (s) + HCl (aq)
Reaction with marcuric chloride: Hg2Cl2 is first formed by adding marcuric chloride solution to the stannous chloride solution, which is reduced by the addition of stannous chloride to Hg.
SnCl2 + 2HgCl2→ SnCl4 + Hg2Cl2
Hg2Cl2 + SnCl2→ SnCl4 + 2Hg
Reaction with ferric chloride: It reduces the ferric chloride to ferrous chloride.
2FeCl3 + SnCl2→ 2FeCl2 + SnCl3
Reaction with iodine: In the presence of HCl acid, it also reduces iodine.
I2 + 2HCl + SnCl2→ SnCl4 + 2HI
Reaction with NaOH: It reacts with NaOH to form stannous hydroxide precipitates which dissolve in excess of NaOH and dissolve sodium.
SnCl2 + 4NaOH → 2NaCl + 2H2O + Na2SnO2
Reaction with H2S gas: Black precipitate of stannous sulfide is obtained when hydrogen sulfide gas flows in the stannous chloride solution, which dissolves in the yellow ammonium sulfide solution.