1. CH₃COONH₄ A normal salt formed by the neutralization of acetic acid with ammonium hydroxide; a white, crystalline, deliquescent material used in solution for the standardization of electrodes for hydrogen ions.

2. CH₃COONH₄·CH₃COOH An acid salt resulting from the distillation of the neutral salt or from its solution in hot acetic acid; crystallizes in deliquescent needles.

3. A mixture of the normal and acetic salts; used as a mordant in the dyeing of wool.