Kp = Kc(RT)Δng or Kc = \(\frac{K_p}{(RT)^{\Delta ng}}\)
KP = 2.0 x 1010 bar-1
R = 0.083 L bar K-1 mol-1
T = 450 K
Δng = 2 - 3 = -1
Kc = \(\frac{(2.0 \times 10^{10}\,bar^{-1})}{[(0.083\, L\, bar\, k^{-1}\, mol^{-1})\times (450\, K)]^{-1}}\)
Kc = (2.0 x 1010 bar-1) x (0.083 L bar K-1 mol-1) x (450 K)
= 7.47 x 1011 mol L-1 = 7.47 x 1011 M-1.