[Free Registration/Login may be required to access all resource tools.] In the following online tutorial students will learn to calculate the amount in moles of a reactant or product from the mass of another reactant or product. They will also learn to calculate the mass of a reactant or product from the moles of another reactant or product. Students will create volume ratios from a balanced chemical equation and use volume ratios and other stoichiometric principles to solve problems involving mass, molar amounts, or volumes of gases.