Students know one mole equals 6.02 x 1023 particles (atoms or molecules). Students know how to determine the molar mass of a molecule from its chemical formula and a table of atomic masses and how to convert the mass of a molecular substance to moles, number of particles, or volume of gas at standard temperature and pressure. For chemistry you often need to convert moles to grams and grams to moles. There is a simple relation between these two:, where - mass of the substance in grams - quantity of the substance in moles - molar mass of the substance in grams/mole. And the most difficult task here is finding out the molar mass of the substance.

May 08, 2018 · In chemistry courses, you’ll frequently have to convert moles to molecules or molecules to moles using Avogadro’s number. To do this, you’ll want to be familiar with the definitions of both moles and molecules, the relationship between the two concepts, and the exact formula which uses Avogadro’s number.