Answer:
0.585 moles Na₂SO₄
Step-by-step explanation:
To find the amount of moles of Na₂SO₄, you need to multiply the given mass (grams) by the molar mass. You can use the molar mass to convert between grams and moles because the molar mass exists as a ratio which compares the mass of Na₂SO₄ per every 1 mole. The ratio should be arranged in a way that allows for the cancellation of units (grams should be in the denominator). The final answer should have 3 sig figs like the given value.
Atomic Mass (Na): 22.990 g/mol
Atomic Mass (S): 32.065 g/mol
Atomic Mass (O): 15.999 g/mol)
Molar Mass (Na₂SO₄): 2(22.990 g/mol) + 32.065 g/mol + 4(15.999 g/mol)
Molar Mass (Na₂SO₄): 142.041 g/mol
83.1 grams Na₂SO₄ 1 mole
-------------------------------- x -------------------------- = 0.585 moles Na₂SO₄
142.041 grams