How is molarity defined?

Molarity is defined as the number of moles of solute per liter of solution. This definition emphasizes the relationship between the quantity of dissolved substance (solute) and the total volume of solution in which it is contained. Molarity is typically expressed in moles per liter (mol/L), making it a crucial concentration unit in chemistry.

Understanding molarity is essential for stoichiometric calculations, where it allows chemists to determine how much of a reactant is needed or how much product will be formed in a chemical reaction when the concentrations of reactants are known. This concept plays a vital role in various applications, such as titrations and dilutions, where the precise concentrations of solutions are critical for achieving accurate results.

In contrast, the other options mention mass or weight, which relates to other forms of concentration, such as molality or the mass/volume percentage. However, molarity specifically focuses on the mole—providing a clear connection to the particle nature of substances in solution.