JEE Main Chemistry question
At temperature T, a compound AB₂(g) dissociates according to the reaction 2AB₂(g) ⇌ 2AB(g) + B₂(g) with a degree of dissociation x, which is small compared with unity. The expression for Kp, in terms of x and the total pressure P, is:
Answer: (C)
Solution
Starting 2 mol AB₂, at eq. total moles≈2 (x small). Mole fractions: AB≈x, B₂≈x/2, AB₂≈(1−x). Kp≈[(xP)²(xP/2)]/P² = Px³/2.