11. Conservation of Mass, Charge, and       Energy   Previous PageNext Page
      PROBLEMS
3. If plenty of oxygen is available, iron burns to form black Fe3O4.

(a)1Write the balanced equation for the reaction.
(b)1How many moles of O2 are required to burn one mole of iron?
(c)1How many grams of O2 are required to burn one mole of iron?
(d)1Can a piece of iron weighing 5.6g burn completely in a vessel containing 0.05 mole of O2?

4. Write the oxidation number of each atom in the following compounds:

(a) nitric acid (f) permanganate ion, MnO4
(c) potassium oxide (g) cuprous oxide, Cu2O
(b) potassium hydroxide (h) cupric oxide, CuO1
(d) ammonia (i) magnetite Fe3O4
(e) potassium permanganate (j) iron pyrite, FeS2

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