132 g/mol
Explanation:
(NH₄)₂SO₄ has 2 nitrogen atoms, 8 hydrogen atoms, 1 sulfur atom, and 4 oxygen atoms.
From the periodic table, the molar mass of each element is:
N: 14.0 g/mol
H: 1.01 g/mol
S: 32.1 g/mol
O: 16.0 g/mol
So the molar mass of the compound is:
2N × (14.0 g/mol N) + 8H × (1.01 g/mol H) + 1S × (32.1 g/mol S) + 4O × (16.0 g/mol O)
= 28.0 + 8.08 + 32.1 + 64.0 g/mol
= 132 g/mol
If you need more precision, use more significant figures for the element molar masses.