A25 Reactions of Tin(II) Chloride and Mercury(II) Chloride

Description
Two solutions are mixed in different proportions. When tin(II) is in excess mercury (black) is formed, but when tin(II) is a limiting reagent mercury(I) chloride(white) is formed.

Equation
Sn²⁺ + 2Hg²⁺ + 2Cl^- --> Sn⁴⁺ + Hg₂Cl₂ (white)

Sn²⁺ + Hg²⁺ --> Sn⁴⁺ + Hg (black)

Reference