Nature of Equilibrium

Dynamic Equilibrium

In this course, Professor Karl Haushalter (Harvey Mudd College) introduces the topic of dynamic equilibrium, a unique state of a chemical reaction with unique properties. Understanding these properties is central to optimising industrial reactions. We begin by (i) describing what dynamic equilibrium is by looking at the interconversion of dinitrogen tetroxide into nitrogen dioxide, seeing how dynamic equilibrium differs from a complete reaction; (ii) moving on to how we measure the state the equilibrium using the equilibrium constant K_C, then (iii) looking at how we can use K_C to predict reactions, and applying this knowledge to some problems; then (iv) looking at and working through some ICE (Initial, Change, Equilibrium) calculations; before (v) understanding Le Chatelier’s principle; and finally (vi) briefly considering the connections of dynamic equilibrium to thermodynamics and kinetics.

Nature of Equilibrium

In the first mini-lecture we start to define dynamic equilibrium by looking at the interconversion of dinitrogen tetroxide to nitrogen dioxide. What observations can we make about a reaction in dynamic equilibrium, when the product is coloured and the reactant is clear? We address some of the common misconceptions of a chemical reaction in dynamic equilibrium: one being that one might assume the reaction is no longer taking place since there is no observable change in colour of the reaction vessel. Additionally, we briefly touch on some other reactions in dynamic equilibrium, including the interconversion of two allotropes of carbon: diamond and graphite.