When sodium hydroxide dissolves in water, it separates completely into sodium ions and hydroxide ions. This complete separation makes it a strong base. The process releases a large amount of heat.
Students often mistake this physical release of heat for a chemical reaction. The high level of hydroxide ions makes the solution highly basic. This solution can cause severe chemical burns by breaking down proteins in human skin.
Many students confuse the terms strong and concentrated. A strong base is one that splits completely into ions, even in a dilute solution. The solid form is deliquescent, meaning it absorbs water from the air until it dissolves.
If left open, a dry pellet will soon turn into a corrosive liquid puddle. Industries make sodium hydroxide on a large scale using the chlor-alkali process. This method passes electricity through salt water to make the base, chlorine, and hydrogen.
In factories, the chemical helps turn wood into paper pulp by dissolving lignin. It also serves as a key ingredient in making soaps, synthetic fibers, and clean drinking water. Water treatment plants use it to adjust pH levels and remove toxic heavy metals.
The base reacts with soluble metal ions to form solid metal hydroxides that settle out of the water. Chemists also use this base in laboratories to perform titration experiments.