Nessler's reagent is used to detect small concentrations of ammonia. A yellow coloration indicates the presence of ammonia. At high concentrations, a brown precipitate may form.
Toxicity
It is toxic if swallowed, inhaled or absorbed through the skin. It presents neurological hazard and may act as a carcinogen and be a reproductive hazard. It is corrosive and causes burns. Always wear safety glasses and gloves and manipulate in a well ventilated environment.
Molecular formula
K2HgI4 (a solution of mercury (II) iodide, typically around 1.4%, in acaZZOus potassium iodide and potassium hydroxide.)
Other names
Nessler's solution, mercuric potassium iodide, mercury (II) potassium iodide, Channing's solution, potassium mercuric iodide, potassium tetraiodomercurate (II)