What is the total volume of gases produced at 819 K and 1. atm pressure when 320 g of ammonium nitrite undergoes the following decomposition reaction?

Question

NH4NO2 --------> N2(g) + 2H2O(g)

Answer 1

mols NH4NO2 (is that what you meant to type?) = grams/molar mass = about 5 mols but you need to confirm that.
Therefore, you must have produced 5 mols N2 and 10 mols H2O for a total of 15 mol.
Use PV = nRT and solve for V in L.