Table 11.2 [ENDORSED]

[Katie Lam 1B]

In Table 11.2, it lists values of K and Kc for various chemical equilibrium reactions.
For top half of the table, the values of K and Kc are the same for each reaction (ex: K=4.0x10^31 and Kc=4.0x10^31), but for the second half of the table, K and Kc are different for each reaction (ex: K=3.0x10^-11 and Kc=7.3x10^-13).

Why is there this discrepancy?

[Chem_Mod]

K is based on partial pressure. It was discussed in class as Kp. It will differ in number from Kc, which is based on the molar concentrations of the gases. To convert between the two, you can used the Ideal Gas Law (PV=nRT). Because you are multiplying by these constants, you will come out with a slightly different answer, and when calculating the equilibrium conditions, you have to make sure to use partial pressure when using Kp and concentrations when using Kc.