Its vapour density agrees with the molecular formula C302, and this formula is also confirmed by exploding the gas with oxygen and measuring the amount of carbon dioxide produced (see Ketenes).
The molecular formula of a compound, however, is always a simple multiple of the empirical formula, if not identical with it; thus, the empirical formula of acetic acid is CH 2 O, and its molecular formula is C2H402, or twiceTCH 2 O.
There is some doubt as to the molecular formula of fulminic acid.
That orthoboric acid is a tribasic acid is shown by the formation of ethyl orthoborate on esterification, the vapour density of which corresponds to the molecular formula B(0C2H5)3; the molecular formula of the acid must consequently be B(OH) 3 or H 3 B0 3.
This fact, coupled with the determination of the vapour density of the gas, establishes the molecular formula CO.