A rigid 10.0 L vessel at 27 °C contains 2.00 g of H₂(g) and 10.0 g of Cl₂(g). The gases react completely according to the equation
H₂ + Cl₂ → 2 HCl(g)
After the reaction is complete and the vessel is returned to 27 °C, what is the final pressure inside the vessel?
a) 5.6atm
b) 3.1atm
c) 2.8atm
d) 2.4atm