How do I solve this

Question

Solid sodium reacts with liquid water to form hydrogen gas according to the equation 2Na(s)+2H2O(l)=2NaOH(aq)+H2(g)

what is the pressure in atm of hydrogen gas in the 20.0 L headspace of a reactor vessel 11.52 Kg sodium is reacted with excess water at 50.0 Celsius

Answer 1

2Na(s) + 2H2O(l) = 2NaOH(aq) + H2(g) ... balanced equation

moles Na reacted = 11.52 kg x 1000 g/kg x 1 mol Na/23 g = 501 moles Na

Using the ideal gas law PV = nRT and solving for P, we have...

P = nRT/V = (501 mol)(0.0821 Latm/Kmol)(323K) / 20 L

P = 664 atm