What is the chemical formula for a primary alcohol?

The chemical formula for a primary alcohol is represented as CnH2n+1OH. This formula illustrates that for any given number of carbon atoms (n), a primary alcohol will have twice as many hydrogen atoms plus one additional hydrogen atom, in addition to a hydroxyl group (–OH).

In this case, "primary" refers to the structure of the alcohol, where the hydroxyl group is attached to a carbon atom that is connected to only one other carbon atom. This structure fulfills the requirement for the general alkane formula, which has the form CnH2n+2, but modifies it by replacing one hydrogen atom with the hydroxyl group, leading to a net formula of CnH2n+1OH.

Understanding this distinction clarifies why the other choices do not correctly represent the structure of a primary alcohol. For example, CnH2nOH would imply a different ratio of hydrogen to carbon, indicating a different type of compound (typically an alkene), while CnH2n+2OH would not be possible as it suggests more hydrogens than allowed for alcohols. The equivalent representation of CnH2n-1OH mistakenly suggests a structure that does not fit the characteristics of alcohol