How many GRAMS of aluminum sulfite are present in 3.04 moles of this compound? How many MOLES of aluminum sulfite are present in 1.16 grams of this compound?

Question

1. How many GRAMS of aluminum sulfite are present in 3.04 moles of this compound?______ grams.

2. How many MOLES of aluminum sulfite are present in 1.16 grams of this compound?______ moles.

Answer 1

First, calculate the molar mass using the periodic table. The formula is Al₂(SO₃)₃, so its molar mass is (to 3 sig figs) 294 g/mol.

Thus, to find the mass of 3.04 mol we would do the dimensional analysis as follows:

(294 g / 1 mol) x 3.04 moles = 999.6 ≅ 1000 or 1.00 x 10³ grams

The reverse calculation will get you from grams to moles:

(1 mol / 294 g) x 1.16 g ≅ 3.95 x 10^-3 mole