What is the general formula for alcohols?

The general formula for alcohols is represented as ROH. In this formula, "R" stands for an alkyl group, which can vary in length and complexity, and "OH" is the hydroxyl group that characterizes alcohols. The inclusion of the hydroxyl group is crucial, as it is responsible for the properties and behavior associated with alcohols, including their solubility in water and their reactivity.

Each of the other options represents different classes of organic compounds. For instance, RCHO corresponds to aldehydes, where the carbonyl group (C=O) is attached to a hydrogen atom and an alkyl group. RCOR represents ketones, which contain a carbonyl group between two alkyl groups. C2H6 is the molecular formula for ethane, an alkane, which consists solely of carbon and hydrogen atoms without the hydroxyl functional group.

Therefore, the definition of alcohols requires the presence of the hydroxyl functional group, making ROH the correct representation of their general formula.