Answer:-
3.2 grams
Explanation:-
The chemical formula for Magnesium Oxide is MgO.
The balanced chemical equation for this reaction is
2Mg + O2 --> 2MgO
Atomic weight of Mg = 24 grams
Molecular weight of oxygen gas O2 = 16 x 2 = 32 grams.
Molecular weight of MgO = 24 x 1 + 16 x 1 = 40 grams
From the balanced chemical equation we see
To produce 2 MgO we require 1 O2.
∴ To produce 2 x 40 grams of MgO we require 32 grams of Oxygen.
To produce 8 grams of MgO we require 32 x 8 / ( 2 x 40) grams of oxygen
= 3.2 grams of oxygen
