Molarity is represented by the capital letter M, and it has the unit moles of solid over volume of solution. And this includes the volume of both the solvent and the solid. Now let's do an example using molar. The question tells us that we have 0.6 liters of a three molar solution. We need to find the number of liters that we need to add to go from three molar to a one molar solution. So we're diluting.