To calculate the molar mass of ammonium sulfate NH4 2SO4 , we need to find the molar mass of each element in the compound and then add them together.Ammonium NH4 has 1 nitrogen atom and 4 hydrogen atoms:- Nitrogen N has a molar mass of 14.01 g/mol.- Hydrogen H has a molar mass of 1.01 g/mol.So, the molar mass of one NH4 is 1 x 14.01 + 4 x 1.01 = 14.01 + 4.04 = 18.05 g/mol.Since there are two ammonium ions in the compound, the total molar mass of the ammonium ions is 2 x 18.05 = 36.10 g/mol.Sulfate SO4 has 1 sulfur atom and 4 oxygen atoms:- Sulfur S has a molar mass of 32.07 g/mol.- Oxygen O has a molar mass of 16.00 g/mol.So, the molar mass of SO4 is 1 x 32.07 + 4 x 16.00 = 32.07 + 64.00 = 96.07 g/mol.Now, we add the molar mass of the ammonium ions and the sulfate ion to get the molar mass of ammonium sulfate NH4 2SO4 :Molar mass of NH4 2SO4 = 36.10 + 96.07 = 132.17 g/molRounded to the nearest hundredth of a gram, the molar mass of ammonium sulfate is 132.17 g/mol.