What does molarity measure in a solution?

Molarity specifically measures the concentration of a solute in a solution, expressed as moles of the solute per liter of solution. This means that when you calculate molarity, you determine how many moles (a standard measure in chemistry representing a quantity of substance) are present in one liter of the total solution. This is a crucial concept in chemistry because it allows for precise stoichiometric calculations and is fundamental in preparing solutions for various chemical reactions.

The focus on moles rather than mass or volume is what distinguishes molarity from other concentration measures. While mass per volume might seem relevant, it is a different measure known as mass concentration. Similarly, molarity does not concern itself with the volume of the solute specifically or the density of the entire solution, as these factors are not direct indicators of solute concentration. Understanding molarity helps in various applications, including dilutions and titrations, making it a vital concept in water treatment and other areas of chemistry.