Textbook Problem 5G.9

[Katie 3H]

How are the partial pressures for (PO2)/(PO3) different for the two containers but the (PO2)^3/(PO3)^2 and (PO3)^2 /(PO2)^3 same? Shouldn't they all be the same for both containers?

[Joanna Zhao 1J]

(PO2)^3/(PO3)^2 and (PO3)^2 /(PO2)^3 are identical because it is K. The equilibrium constant, K, and its reciprocal, 1/K, is constant at a certain temperature, and both containers are at equilibrium so their Q = K which is the same value. However, because (PO2)/(PO3) is NOT K we cannot be sure that the ratios are the same. We'd have to use an ICE chart to determine the equilibrium pressures of each and manually calculate that ratio for each individual container.

[Qinyan Feng 1H]

Hi

Just to add on, when (PO2)^3/(PO3)^2 and (PO3)^2 /(PO2)^3 are the same in two containers, (PO2)/(PO3) can never be the same unless PO2 = PO3 in two containers, based on the math.