Answer:
56.96 grams
Step-by-step explanation:
To find the mass of 1.78 moles of O2, we need to use the molar mass of O2, which is the mass of one mole of O2.
The chemical formula for O2 is O-O or simply O2. The molar mass of O2 is the sum of the atomic masses of two oxygen atoms, which can be found on the periodic table.
The atomic mass of oxygen (O) is approximately 16.00 g/mol. So the molar mass of O2 is:
Molar mass of O2 = 2 x atomic mass of O
= 2 x 16.00 g/mol
= 32.00 g/mol
Therefore, the mass of 1.78 moles of O2 is:
Mass = number of moles × molar mass
= 1.78 mol × 32.00 g/mol
= 56.96 g
So the mass of 1.78 moles of O2 is 56.96 grams.