The following molecular models are part of the OUC molecular models database. Comments CH 2 O 2 46.03 Methanoic acid, Formic acid pK a 3.75 Information. Found in rhubarb leaves .
Sodium salt is monoxone.
O 2 60.06 Ethanoic acid, Acetic acid pK a 4.75. Vinegar is an approx. Pk a 3.03 and 4.44. C 4 H 4 O 4 116.08 cis-Butenedioic acid Maleic acid. O 6 174.12 Aconitic acid From leaves and tubers of Aconitum napellus .