While active metals such as sodium are exposed to air, they quickly form a coating of metal oxide. The balanced equation for the reaction of sodium metal with oxygen gas is
Na(s) + O2(g) ? Na2O(s)
Presume a piece of sodium metal gains 2.05 g of mass after being exposed to air. Presume that this gain can be attributed to its reaction with oxygen.
a. Explain what mass of O2 reacted with the Na?
b. Define what mass of Na reacted?
c. Define what mass of Na2O formed?