C-06-Q135mediumsingle_mcqIn 2Mg+O2→2MgO\mathrm{2Mg + O_2 \to 2MgO}2Mg+O2→2MgO, O2\mathrm{O_2}O2 needed to produce 10 g MgO is—a2 gb4 gc8 gd16 g