Select the true statements from the following. If the molecular weight of O2 is 32.0g/mol, one half of a mole of O2 has a mass of 16.0 grams. If the empirical formula of a substance is NO2 and its molecular weight is 92.0 g/mol, its molecular formula is N2O4. The balanced equation 1O2+2H22H2O indicates that 2 moles of oxygen would be required to completely react with 2 moles of hydrogen. 3.011023 atoms is one-half of a mole of atoms