In the equation above, the expression for the equilibrium constant, k\(_c\) is

The equation shown is:

2XY₃(g) ⇌ X₂(g) + 3Y₂(g)

The equilibrium constant \(K_c\) is defined as the ratio of the product concentrations raised to their stoichiometric coefficients divided by the reactant concentrations raised to their stoichiometric coefficients.

From the balanced equation, the products are X₂ (coefficient 1) and Y₂ (coefficient 3), while the reactant is XY₃ (coefficient 2). Therefore:

\[K_c = \frac{[X_2][Y_2]^3}{[XY_3]^2}\]

The coefficients become exponents in the equilibrium expression, not multipliers placed in front of the concentration brackets. This is a fundamental distinction: writing \([2XY_3]\) or \([3Y_2]\) treats the coefficient as part of the concentration term, which is incorrect.