From the given balanced reaction equation:
we can see that every 1 mole of NH4NO2 will produce 1 mole of N2 and when the water also on the gas phase so, every 1 mole of NH4NO2 will produce 3 moles of gas
now we need to get number of moles of NH4NO2 = mass/molar mass
when the mass = 32 g and the molar mass of NH4NO2 = 64 mol/g
∴moles of NH4NO2 = 32 g / 64 mol/g = 0.5 mole
so, the moles that produced of gas will be = 3 * 0.5 = 1.5 moles
now, we can use the ideal gas formula to get V:
PV = nRT
when P is the pressure = 1.5 atm
n is the number of moles = 1.5 moles
R is the ideal gas constant = 0.0821 L*atm/mol*K
and T is the temperature in Kelvin = 525 °C + 273 = 798 K
so by substitution:
1.5 atm * V = 1.5 moles * 0.0821 * 798 K
∴ V = 65.5 L