Ammonia water
Also known as ammonium hydroxide and ammonia water
NH3(aq) + H2O(l) ↔ NH4+(aq) + OH-(aq)
In water, ammonia is readily soluble, giving off heat.
Ammonia water is available at concentrations of up to 32.5%; in Europe, solutions of a concentration of just below 25% are typically used for flue gas denitrification, to account for the risk classification of the process.
