They are soluble in water and give characteristic precipitates with platinic and auric chlorides, and with potassium ferrocyanide.
Again, the diazonium chlorides combine with platinic chloride to form difficultly soluble double platinum salts, such as (C 6 H 5 N 2 C1) 2 PtC1 4; similar gold salts, C 6 H,N 2 C1 AuC1 3, are known.
Double salts of cerous chloride with stannic chloride, mercuric chloride, and platinic chloride are also known.
They give a characteristic pale red precipitate with sodium pyrophosphate, soluble in an excess of the precipitant; they also form precipitates on the addition of platinic chloride and potassium ferrocyanide.