Calculate KC for the reaction at this temperature.?

Assume that the units of pressure of volume are atm and L respectively, and thus R = 0.08206 L atm / (mol K)
Temperature, T = (273 + 900) K = 1173 K

Gas law: PV = nRT and thus n/V = P/RT
[N₂] = P(N₂)/(RT)
[H₂] = P(H₂)/(RT)
[NH₃] = P(NH₃)/(RT)

N₂(g) + 3H₂(g) ⇌ 2NH₃(g) …… Kp = 1.4 × 10⁻⁴

Kc
= [NH₃]² / {[N₂] [H₂]³}
= {P(NH₃)/(RT)}² / {{P(N₂)/(RT)} × {P(H₂)/(RT)}³}
= {P(NH₃)² / (P(N₂) × P(H₂)³} × (RT)²
= Kp × (RT)²
= (1.4 × 10⁻⁴) × (0.08206 × 1173)²
= 1.3