Question

Ammonium nitrate can decompose explosively when heated according to the equation
2NH₄NO₃(s)→2N₂(g)+4H₂O(g)+O₂(g)

How many liters of gas would be formed at 465^∘C and 1.00 atm pressure by explosion of 420 g of NH₄NO₃?

I understnad I must use the ideal gas formula PV=nRT after I find n however, I continue to get stuck there and I can't find how to get past 5.2472 mol NH₄NO₃

Any explanation would be greatly appreciated!