Calculate Kp for the reaction at this temperature.

Question

At a given temperature, 4.595 atm of F2 and 5.404 atm of Br2 are mixed and allowed to come to equilibrium. The equilibrium pressure of BrF is found to be 1.268 atm.

F2(g) + Br2(g) ⇌ 2 BrF(g).  

Answer 1

F₂(g) + Br₂(g) ⇌ 2 BrF(g)

4.595......5.404...........0.........Initial

-x............-x...............+2x.......Change

4.595-x...5.404-x........2x.......Equilibrium

2x = 1.268 atm

x = 0.634 atm

Summary of equilibrium pressures:

P_F2 = 4.595 - 0.634 = 3.961 atm

P_Br2 = 5.404 - 0.634 = 4.77 atm

P_BrF = 1.268 atm

Kp = (P_BrF)² / (P_F2)(P_Br2)

Kp = (1.268)2 / (3.961)(4.77)

Kp = 0.08510