A mol of Carbon Dioxide is equal to the mass of 2 oxygen atoms plus the mass of 1 carbon atom.
Mass of Oxygen atom is 16. 16 x 2 = 32
Mass of Carbon atom is 12.
32 + 12 = 44
So that’s the mass of a mol of CO2. Just multiply that by 4 mols.
44 x 4 = 176 grams