Molarity is the most useful concentration for chemical reaction in solution because it directly relates moles of solute to volume of solution. The definition of molarity is ![]() As an example, suppose we dissolve 23 g of ammonium chloride (NH4Cl) in enough water to make 145 mL of solution. What is the molarity of ammonium chloride in this solution? ![]() Now, suppose we have a beaker with 175 mL of a 0.55 M HCl solution. How many moles of HCl is in this beaker? ![]() As a final example suppose we have a solution of 0.135 M NaCl and we need 1.2 moles of NaCl. What volume of the NaCl solution is required? ![]() |