The mechanism with a ketone and a similar version with an aldehyde is described, where the carbonyl group and pair of electrons belonging to the oxygen react with the hydronium in water.

A clear, step-by-step tutorial which illustrates the steps to balance chemical equations. [4:22]

Hank discusses aromatics and cyclic compounds and naming their substituents, resonance as well as common reactions, and uses. [9:50]

The resource from Khan Academy provides practice questions for the AP Chemistry course. This video lesson explains the concepts of equilibrium reactions and constants.