To calculate molarity, divide the number of moles of solute by the volume of the solution in liters. If you don't know the number of moles of solute but you know the mass, start by finding the molar mass of the solute, which is equal to all of the molar masses of each element in the solution added together. Note: For aqueous solutions of covalent compounds—such as sugar—the molality and molarity of a chemical solution are comparable. In this situation, the molarity of a 4 g sugar cube in 350 ml of water would be 0.033 M. The most typical molarity problem looks like this: What is the molarity of whatever grams of whatever substance dissolved in whatever mL of solution. To solve it, you convert grams to moles, then divide by the volume, like this: The two steps just mentioned can be combined into one equation. How to Find Molarity As long as you have a way of measuring the mass of a solute, you can calculate its molarity by measuring the volume of the solution. Be careful here, because molarity is always expressed as moles/liter, so if you measure volume in any other units, you have to convert to liters. How to Calculate the Concentration of a Solution. In chemistry, a solution's concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. The standard formula is C = m/V. Calculating Molarity : Home: The properties and behavior of many solutions depend not only on the nature of the solute and solvent but also on the concentration of the solute in the solution. Chemists use many different units when expressing concentration; however, one of the most. This molarity calculator is a tool for converting the mass concentration of any solution to molar concentration (or recalculating the grams per ml to moles). You can also calculate the mass of a substance needed to achieve a desired molarity. This article will provide you with the molarity definition and the molarity formula.To understand the topic as a whole, you will want to learn the mole. Molarity is a unit of concentration, measuring the number of moles of a solute per liter of solution.The strategy for solving molarity problems is fairly simple. This outlines a straightforward method to calculate the molarity of a solution.