How many grams of NH3 are produced

At a temperature of 425C and a pressure of 695mmHg, how many grams of NH3 can be produced when 4.5L of NO3 react?
4NO2+6H2O----->7O2+4NH3

Do I use PV=nRT? Please go step by step. Thanks!

425C+273 = 698K
4.5L
0.9144atm 760mmhg=1atm
(0.9144)(4.5L) = (n)(0.0821)(698K)
4.1148 = (n)57.3058
n = 0.072 moles NO2x4 mole nh3/4 mole no2 = 0.072moles NO2x 46g/1mole = 3.312g NH3

Yes, use PV=nRT
695mmHg * 4.5L = n * 62.4 * (425+273)
n = 0.0072 mol NO2

For every 4 moles of NO2 that react, 4 moles of NH3 are produced.

So, if 0.0072 moles of NO2 react, 0.0072 moles of NH3 are produced.