Question

Which of the following is the correct expression for the pressure-based equilibrium constant for the reaction: 2NOBr (g)⇌2NO(g)+Br_2(g)

Options:
Option 1: K_p = ([NO]^2 [Br_2])/[(NOBr)^2]
Option 2: K_p = ([NO] [Br_2])/[NOBr]_2
Option 3: K_p = [NOBr]^2/[NO]^2 [Br_2]
Option 4: K_p = [NOBr]/[NO][Br_2]^2

Answer 1

The correct expression for the pressure-based equilibrium constant (Kp) is given by Option 1: Kp = ([NO]2 [Br2])/[(NOBr)2], using the partial pressures of the reactants and products raised to the power of their coefficients in the balanced equation.

Step-by-step explanation:

To find the correct expression for the pressure-based equilibrium constant, Kp, for the reaction 2NOBr(g) ⇌ 2NO(g) + Br2(g), we must reference the balanced equation and use the partial pressures of the products and reactants. According to equilibrium law, the equilibrium constant expression for a reaction involving gases is the ratio of the partial pressures of the products to the reactants, each raised to the power of its respective coefficient in the balanced equation.

For our reaction, the equilibrium constant expression in terms of partial pressures (Kp) is: Kp = (PNO)2 × PBr2) / (PNOBr)2 which leads us to Option 1: Kp = ([NO]2 [Br2])/[(NOBr)2].