Calculating Kc for the Haber-Bosch equilibrium

Steps:

• Write Kc expression: Kc = [NH₃]² / ([N₂] [H₂]³)
• Calculate numerator: (6.00)² = 36.0
• Calculate denominator: (0.200)(3.00)³ = (0.200)(27.0) = 5.40
• Divide: 36.0 / 5.40 = 6.67 × 10¹ = 66.7

Why D is correct:

• Kc equals 66.7, directly from the equilibrium constant formula using given concentrations.

Why the others are wrong:

• A is the reciprocal of Kc (1/66.7 ≈ 0.015)
• B is [NH₃] / [H₂], ignoring stoichiometry and N₂
• C is [NH₃] / [N₂], omitting H₂ and coefficients

Final answer: D