Write the balanced equation for the following reactions: the decomposition of ammonium nitrate to nitrogen gas, oxygen gas, and water vapor; the reaction of sodium bicarbonate with sulfuric acid to produce sodium sulfate, water, and carbon dioxide; the treatment of phosphorus pentachloride with water to produce phosphoric acid and hydrogen chloride.

Um this is what I got 
a. NH4NO3 > N2O + 2 H2O This is the correct equation ammonium nitrate does not produce oxygen when heated.

If you meant ammonium nitrite, not nitrate, in which case the equation is:
NH4NO2 > N2 + 2 H2O, but this doesn't produce oxygen either. If you teacher is ignorant of these facts, or gave you a bogus problem to solve, then use this equation (even though it doesn't exist): 2 NH4NO3 > 2 N2 + O2 + 4 H2O (Drax an "x' through the yields line to indicate that this reaction actually doesn't take place.

b. 2 NaHCO3 + H2SO4 > Na2SO4 + 2 CO2 + 2 H2O

c. PCl5 + 4 H2O > H3PO4 + 5 HCl

Hope this helped!

The mass has escaped into a gas which you can not see so the law stays true.

The correct answer is "hydrogen".