Identifying Functional Groups in Organic Chemistry

Alcohols contain a hydroxyl (-OH) group in their chemical structure, which is responsible for their distinctive properties.

An aldehyde is characterized by a carbonyl group (C=O) bonded to at least one hydrogen atom. This distinguishes it from other functional groups such as hydroxyl (-OH), amino (-NH2), and carboxyl (-COOH) groups.

A ketone functional group is characterized by the presence of a carbonyl group, which consists of a carbon atom double bonded to an oxygen atom. This distinguishes it from other functional groups such as hydroxyl, amino, and alkyl groups.

Ethers are organic compounds containing an oxygen atom bonded to two alkyl or aryl groups. They are characterized by the functional group -O-.

The correct functional group for carboxyl is COOH, which consists of a carbonyl group (C=O) bonded to a hydroxyl group (OH). The other incorrect options do not represent the carboxyl functional group.

An amide functional group consists of a nitrogen atom joined to a carbonyl group by a single bond and potentially to another atom by a double bond. The incorrect answers do not accurately describe the structure of an amide functional group.

Amine is a functional group characterized by a nitrogen atom bonded to hydrogen atoms or hydrocarbons, whereas alcohol, aldehyde, and carboxylic acid are different functional groups with distinct properties.

Amino acids contain an amino functional group, which consists of a nitrogen atom bonded to two hydrogen atoms.

Esters are organic compounds that contain a carbonyl group (C=O) and an alkoxy group (-OR). They are formed by the reaction between a carboxylic acid and an alcohol, leading to the loss of a water molecule. Esters are commonly used for their pleasant aroma and flavor in essential oils, fragrances, and food industry.

Thiol is characterized by the presence of a sulfhydryl group, which consists of a sulfur atom bonded to a hydrogen atom (-SH). This differs from other functional groups like the alcohol group (-OH), carboxyl group (-COOH), and amino group (-NH2), making it unique in its chemical properties and reactivity.

The correct answer is methane because it is the simplest alkane in the homologous series with the chemical formula CH4.

The homologous series of alkanes refers to a series of organic compounds that have the same functional group but with increasing number of carbon atoms. Ethane specifically has the molecular formula C2H6, denoting two carbon atoms and six hydrogen atoms.

Propane is a three-carbon alkane with the molecular formula C3H8. This means it contains three carbon atoms and eight hydrogen atoms. Incorrect answers: C2H6 is the molecular formula of ethane, C4H10 is the molecular formula of butane, and C5H12 is the molecular formula of pentane.

Pentane belongs to the homologous series of alkanes, which are hydrocarbons with single carbon-carbon bonds. Its molecular formula is C5H12, indicating that it has 5 carbon atoms and 12 hydrogen atoms in its structure. The incorrect answers provided do not represent the correct molecular formula of pentane.