Aqua Ammonia, aqueous ammonia and ammonium hydroxide are synonymous terms referring to a solution of ammonia in water. Aqua ammonia is a clear, colorless liquid with a strong pungent ammonia odor.
The grade or strength of commercially available aqua ammonia is usually 26-Degree Baumé. However, any strength can be custom blended to meet project requirements.
The Baumé reading refers to a specific gravity scale. A 26-Degree Baumé solution is equivalent to 29.4% by weight of ammonia dissolved in water. Since the Baumé reading varies with temperature, the reading is standardized at 60° F.
Aqua ammonia is classified as a weak base. It ionizes much less completely in water than does a strong base such as sodium hydroxide.
Aqua ammonia is corrosive to copper, copper alloys, aluminum alloys and galvanized surfaces. The base solution is an excellent acid neutralizer. Its pH varies with concentration. Typical values are 11.7 at 1%, 12.2 at 5%, 12.4 at 10% and 13.5 at 30%.