A saturated solution at 25 C is 12M in HCl. It is very soluble in water. A saturated solution is 18M in NaOH at 20 C. Solutions of sodium hydroxide are very corrosive to the skin and other organic matter. Hence, its name in commerce is caustic soda. The paper industry uses the caustic effects of sodium hydroxide on organic materials.
Sodium hydroxide breaks down the lignin in wood.
Lignin is a binder that holds cellulose fibers together in wood. When the lignin is removed, the freed cellulose fibers can be formed into paper. The digestive effects of sodium hydroxide on organic materials is the principle behind such drain cleaners as Liquid Plumr, which is a concentrated aqueous solution of sodium hydroxide. These salts are soaps. Similar salts of synthetic acids containing long chains of carbon atoms are detergents.