Consider the reaction: \( \mathrm{X_2Y(g) \rightleftharpoons X_2(g) + \tfrac{1}{2}Y_2(g)} \)
The equation representing correct relationship between the degree of dissociation \( x \) of \( \mathrm{X_2Y(g)} \) with its equilibrium constant \( K_p \) is __________. Assume \( x \) to be very very small.
