The
amount of a substance can be converted into grams of that substance by using
the molar mass. It is a physical property of a substance which describes the
mass per mole of the substance. The molar mass
of MgS2O3 is 136.4332 g/mol. Dividing the molar mass of MgS2O3 from the given amount will yield the moles of MgS2O3
195 g MgS2O3 / 136.4332 g/mol = 1.43 mol MgS2O3
