What is the general formula for an alcohol?

The general formula for an alcohol is represented as CnH2n+1OH. This formula indicates that for every n carbon atoms present in the alcohol, there are 2n+1 hydrogen atoms, along with one hydroxyl group (—OH). The hydroxyl group is what characterizes alcohols and differentiates them from other hydrocarbons.

This formula reflects the structure of primary, secondary, and tertiary alcohols, all of which contain the —OH functional group bonded to a carbon atom. The presence of this functional group is essential for the properties and reactivity of alcohols in various chemical processes.

In contrast, the other formulas provided do not accurately represent the structure of alcohols. For instance, CnH2nO2 typically represents carboxylic acids or esters rather than alcohols, while CnH2n+2 describes the general formula for saturated hydrocarbons, such as alkanes. Lastly, CnH2n-1OH does not correctly denote the relationship between the number of carbons and hydrogens in a typical alcohol, as it implies a hydrogen deficiency that does not fit with the standard alcohol structure.