Ammonia solution
Ammonia solution, also known as ammonia water, ammonium hydroxide, ammoniacal liquor, ammonia liquor, aqua ammonia, aqueous ammonia, or (inaccurately) ammonia, is a solution of ammonia in water. It can be denoted by the symbols NH(aq). Although the name ammonium hydroxide suggests an alkali with composition [NH][OH], it is actually impossible to isolate samples of NHOH. The ions NH and OH do not account for a significant fraction of the total amount of ammonia except in extremely dilute solutions.
Hydrogen halide
The hydrogen halides are diatomic molecules with no tendency to ionize in the gas phase (although liquified hydrogen fluoride is a polar solvent somewhat similar to water). Thus, chemists distinguish hydrogen chloride from hydrochloric acid. The former is a gas at room temperature that reacts with water to give the acid. Once the acid has formed, the diatomic molecule can be regenerated only with difficulty, but not by normal distillation. Commonly the names of the acid and the molecules are not clearly distinguished such that in lab jargon, "HCl" often means hydrochloric acid, not the gaseous hydrogen chloride.