AMMONIUM ACETATE
Formula: CH3COONH4; MW 77.08
Uses
Ammonium acetate is used for preserving meats; as a mordant in the dyeing of wool; in analytical chemistry for standardization of electrodes, and in titrations; also as a therapeutic diuretic and diaphoretic.
Physical Properties
White crystalline solid; deliquescent; melts at 114°C; decomposes at elevated temperatures; density 1.17 g/cm3 at 20°C, density of a 10% solution 1.022 g/mL, and a 50% solution 1.092 g/mL; very soluble in cold water (1,480 g/L at 4°C); also soluble in cold alcohol and acetone (78.9 g/L in methanol at 15°C); solution loses ammonia on standing and becomes acidic.
Preparation
Ammonium acetate is made by exact neutralization of acetic acid with ammonia to neutral pH (pH 7):
CH3COOH + NH3 →CH3COONH4
Instead of aqueous solutions, hot glacial acetic acid and anhydrous ammonia may be used. Ammonium acetate also is prepared by reaction of acetic acid with ammonium carbonate:
CH3COOH + (NH4)2CO3 → 2CH3COONH4 + CO2 + H2O
Reactions
Ammonium acetate forms an acid salt, ammonium acetate double salt, with hot acetic acid:
CH3COONH4 + CH3COOH → CH3COONH4 •CH3COOH
The acid salt readily dissolves in water and melts at 66°C. Water-insoluble lead iodide dissolves in amonium acetate solution, lead acetate and ammonium iodide are formed:
PbI2 + 2CH3COONH4 → (CH3COO)2Pb + 2NH4I
Tags: ACETATE, AMMONIUM, AMMONIUM ACETATE
