STANNIC CHLORIDE, SNCL₄ :

It can also be obtained by distilling tin with mercuric chloride.

Sn + 2 HgCl₂ ———> SnCl₄ + 2Hg

(a) It is a colorless fuming liquid (b.p 388 K ) soluble in water.

 It is used as a strong reducing agent in laboratory. It is also used as a mordant in dyeing.

(b) It can exist as SnCl₄.5H₂O and with excess water it is hydrolyzed to form basic chloride and ultimately stannic acid (H₂SnO₄).

SnCl₄ + H₂O ———> Sn(OH)Cl + HCl

Sn (OH)Cl + 3 H₂O ———> Sn(OH)₄ or H₂SnO₄ + 3 HCl

Its hydrolysis is prevented by HCl which forms complex anion [SnCl₆]^2–

(c) It forms double salts with NH₃, N₂O, PCl₅ e.g., SnCl₄.4NH₃ .

It is used as a mordant and tinning agent.