11.25 [ENDORSED]

[veneziaramirez 3I]

Why is the answer Kc = [HI]^2/ [H2][I2] instead of P[HI]^2/P[H2]P[I2]?

[Patricia Macalalag 2E]

I believe it's because the problem asks for equilibrium concentration, rather than partial pressure. If you look at 11.27, it asks for partial pressure instead, and you would use the notation with "P."

[Hellen Truong 2J]

Also when you write partial pressures, you don't need the brackets because those indicate concentration!