UTC: Thursday, February 21st, 2019

‘Expanded LCP’ or ‘Q versus K’ explanations?

It’s never been OK, on the AP exam, to offer a simple, ‘because of Le Châtelier’s principle‘ argument as the explanation for the shift of an equilibrium position caused by an external stress. This is in much the same way that it has never been acceptable to say, ‘because as you go across the period first […]

Inert gases and gaseous equilibrium mixtures

What happens when an inert gas is added to a gaseous equilibrium mixture at constant volume? Before we answer that question, it might be worth defining what we mean by “an inert gas”. In this context we mean a gas that is not involved in the equilibrium reaction, or one that reacts with any of […]

Making sense of ∆G and ∆G°, when it comes to equilibrium

Consider the two** equations that deal with Delta G (∆G). **Since this post was originally written in January 2012, the AP exam has changed. One of the changes was to remove equation #2 below from the equations & constants sheet. As such, I think that knowledge of it, and the consequences associated with it, are […]