What type of formula is represented by the notation HCHO?

The notation HCHO represents a molecular formula. A molecular formula provides the actual number of atoms of each element in a molecule, reflecting the composition of the compound. In this case, HCHO indicates that the molecule consists of one carbon atom (C), two hydrogen atoms (H), and one oxygen atom (O). This directly conveys the makeup of the compound formaldehyde.

An empirical formula, in contrast, would show the simplest whole-number ratio of the different elements in the compound, which for HCHO (formaldehyde) would be CH2O, rather than the specific counts of each atom as given in a molecular formula. A line formula, on the other hand, visually represents the structure of the molecule, typically showing the connections between atoms rather than just the count of each type of atom. Lastly, a general formula expresses a broader representation that can apply to a series of compounds, like alkanes, and is not specific to a single molecular entity.

Understanding that HCHO specifically indicates the actual number of atoms in the formaldehyde molecule is key to recognizing it as a molecular formula.