What is the general formula for ketones?

The general formula for ketones is represented as RCOR, where R stands for hydrocarbon groups, which can be either alkyl or aryl groups. This structure indicates that ketones contain a carbonyl group (C=O) positioned between two carbon atoms, distinguishing them from aldehydes, which have the carbonyl group at the end of a carbon chain.

In this context, "R" can represent a variety of carbon-containing groups, allowing for a broad classification of ketones. The presence of the carbonyl group in the middle of the molecule affects the chemical properties and reactivity of ketones, making them significant in various chemical reactions and syntheses.

The other choices reflect different types of organic compounds: "RCHO" denotes aldehydes, "ROH" indicates alcohols, and "C2H6" represents ethane, which does not fit within the classification of functional groups with a carbonyl. Thus, recognizing the structure and formula associated with ketones is crucial in distinguishing them from other organic compounds.