Here 2 moles of N2 also present that is why 2 moles always have to add in total mole calculation. At equilibrium, Pressure (P)=2.46atm Volume (V)=200L Temperature (T)=600K ∴ Applying ideal gas equation, PV=nRT ⇒2.46×200=(7+x)×0.082×600 ⇒x=3 Now, KP=