The molar mass of (NH4)2SO4 is approximately 132.13 grams per mole. The molar mass is found by summing the mass of each atom contained within the compound.
For the compound (NH4)2SO4, the molar mass is the sum of two atoms of nitrogen, eight atoms of hydrogen, one atom of sulfur and four atoms of oxygen. One atom of sulfur has a mass of 32.06 grams per mole; one atom of oxygen has a mass of 15.99 grams per mole; one atom of nitrogen has a mass of 14 grams per mole; and one atom of hydrogen has a mass of approximately 1.01 grams per mole. The mass of each atom can be found in its atomic weight listing on the periodic table of elements.