Molarity is a fundamental concept in chemistry that measures the concentration of a solute in a solution. It is defined as the number of moles of solute per liter of solution. The formula for calculating molarity is: Molarity (M) = moles of solute / liters of solution. For example, if you dissolve 0.5 moles of NaCl in 2 liters of water, the molarity of the solution would be 0.25 M. Molarity is important in various chemical calculations, such as determining the amount of reactants needed in a reaction or predicting the outcome of a chemical reaction. Molarity can also be used to calculate the dilution of a solution. By adding more solvent (usually water) to a concentrated solution, the molarity decreases. The dilution formula is: M1V1 = M2V2, where M1 and V1 are the initial molarity and volume, and M2 and V2 are the final molarity and volume after dilution. Understanding molarity is crucial for students studying chemistry, as it provides a quantitative way to describe the properties of a solution. By mastering this concept, you will be able to perform various chemical calculations accurately and efficiently.