Kp uses the partial pressure of the products (right hand side) and the reactants (left hand side). So for solids and liquids their partial pressures are constant at a certain temperature. But what about gases? At a certain temperature won't the partial pressure also be constant? By using PV=nRT P=nRT/V so V, R, n and T are constants so why is the partial pressure of the gas only used?
For Kc it uses the concentrations. In my book that stated that the concentration of solids and liquids as concentration=amount (in mol)/volume. Since the number of moles is calculated as mass/molar mass, concentration=mass/(molar massXvolume)=density/molar mass? If say A(s)+B(l)
C(s)+D(g) then for A and B, won't the concentration be number of moles of A/volume of A and B? So if I had 1 moles of A and B each and 2 of each won't the concentration be different because now my volume is not just of A but includes B as well? Also, what about gases and aqueous solutes why are their concentrations considered to be not fixed? Shouldn't they be fixed as well?
Lastly, even if the solids and liquids partial pressure or concentration are fixed why can't they be in the equation? Or is this because it would give unnecessary information that would make it harder?
Thanks for the help