Organic Compounds - Their Structure And Reactions

Leave a glass of wine open on a warm windowsill for a fortnight and it turns into something you would put on a salad rather than something you would drink. Nothing was added to it. No one heated it. A colony of bacteria drifting in the air landed on the surface, went to work on the ethanol, and handed back a different substance with a sharp smell and a sour taste. That substance is ethanoic acid, and the whole of this lesson lives in the small structural difference between the molecule the wine started with and the molecule it finished with.

Three families of compound are on the table here, and each one is defined by a single cluster of atoms bolted onto the end of a carbon chain. Change the cluster and you change everything the compound will do: one family dissolves to give a neutral solution and burns cleanly enough to run a car, the second fizzes with carbonates and turns indicator red, and the third is responsible for the smell of pear drops, strawberries and most of the perfume counter. You will learn to spot each family from a formula, to write balanced equations for what they do, and to explain why an acid can be genuinely acidic and still be called weak.