Nomenclature and Structure of Carboxylic Acids

Formaldehyde ($\text{HCHO}$, methanal), the simplest possible aldehyde, is manufactured on an enormous industrial scale and used chiefly for two purposes. First, it is the essential starting material for phenol-formaldehyde resin (commercially known as Bakelite), one of the earliest fully synthetic plastics, made by the condensation polymerisation of formaldehyde with phenol; this resin remains important today as an electrical insulator and in laminates, adhesives and moulded products. Second, a $37$-$40\%$ aqueous solution of formaldehyde, sold and used under the name formalin, is widely used as a biological preservative (for anatomical and pathological specimens) and as a disinfectant/germicide, exploiting formaldehyde's ability to cross-link proteins and so denature and preserve biological tissue.

Acetone ($\text{CH}_3\text{COCH}_3$, propan-2-one), the simplest ketone, is valued above all as a general-purpose organic solvent. Because it is a small, polar molecule that is nonetheless fully miscible with water, and because it can also dissolve a very wide range of non-polar and moderately polar organic substances (resins, plastics, lacquers, fats and oils), acetone bridges the gap between purely aqueous and purely non-polar solvent systems in a way few other common solvents can. It also has a conveniently low boiling point ($56\,^\circ\text{C}$), so it evaporates quickly and cleanly, leaving no residue -- this is exactly why it is the active ingredient in most household nail-polish removers, and why it is used industrially as a solvent for paints, varnishes and adhesives. Acetone is additionally an important starting material for the synthesis of other organic chemicals, notably methyl methacrylate (used to make acrylic plastics such as Perspex). …