Preparation of silver tetraiodomercurate(II)
Mercuric iodide is precipitated by mixing solutions containing 6.8g of mercuric chloride and 8.3g of potassium iodide. The washed material is dissolved in 50ml of water containing a similar quantity of potassium iodide, and mixed with 8.5g of silver nitrate in 150ml of water. Yield, quantitative.
Inorganic laboratory preparations, by G. G. Schlessinger, 97, 1962