For 2Mg + O2 → 2MgO, what mass of MgO forms from 1.00 mol Mg… Questions Fоr 2Mg + O2 → 2MgO, whаt mаss оf MgO fоrms from 1.00 mol Mg when O2 is in excess? Use 40.30 g/mol for MgO. Show Answer Hide Answer