7th Edition 5G.3

[Olivia L 4E]

This is a basic equilibrium constant question, but I'm confused on why the answer for this has a "P" then the chemical formula whereas in class we didn't do that. Do we need the "P" and what does it even mean?

[Gary Qiao 1D]

Yes, generally when the equilibrium constant deals with an equation with only gases in the formula K= [Producrs]/[Reactants], we use partial pressure as the concentration, labeled as "P". There really isn't a difference in the calculations when writing "P" and without it, but if you are dealing with gases it is the right conceptual way to write out the equilibrium constant (Kc) formula as a Kp formula.