formality

The term "formality" can refer to customary good manners, such as a polite gesture or greeting. It can also describe actions performed according to tradition or rules, like those in a religious ceremony.1

In chemistry, "formality" is a measure of concentration for solutions, particularly for compounds that don't exist as discrete molecules, such as sodium chloride. It's defined as the number of formula weights of a substance per liter of solution. This is distinct from molarity, which is based on molecular weights and used for substances that do exist as molecules. Solutions themselves are homogeneous mixtures where one substance dissolves another, a process influenced by chemical nature, temperature, and pressure.23