Synthesis of Silver(I) tetraiodomercurate(II)

11.38 of mercury(II) iodide is combined with a solution prepared from 8.3 g of potassium iodide in 50 mL of water with stirring. Then a solution of 8.5 g of silver nitrate in 150 mL of water is added to the first solution with stirring, the mixture is filtered, washed with water and dried in open air.

HgI₂ + 2 KI = K₂HgI₄

K₂HgI₄ + 2 AgNO₃ = Ag₂HgI₄ + 2 KNO₃

Source

Dissolution of the product

The intermediate compound

Addition of the solution

The mixture after completion

The product exhibiting thermochromism