How does dilution affect molarity?

Molarity refers to the moles of a solute per liter of a solution or in other words, the amount of a substance in a specific volume of solution. It is also known as the molar concentration of a solution. 

Dilution reduces the molarity of the solution. When additional water is added to an aqueous solution, the volume of the solution increases but the moles of the solute do not change. This decreases the concentration and molarity of the solution. As more water is added to the solution, the concentration and molarity of the solution keep decreasing.