Question

Number of different types of functional groups in the given compound is (A) 2 (B) 3 (C) 4 (D) 5

Short answer

In the given compound, \(CH_3CH(OH)CH_2NHCOCH_3\), there are three distinct functional groups present: alcohol (OH), amine (NH), and amide (NHCO). The correct answer is (B) 3.

Step-by-step solution

Alcohol

Find the alcohol functional group in the given compound: CH_3CH(OH)CH_2NHCOCH_3. Here, the alcohol group is (OH) bonded to a carbon atom.

Amine

Identify the amine functional group in the given compound: CH_3CH(OH)CH_2NHCOCH_3. In this compound, the amine group is (NH) bonded to a carbon atom.

Amide

Locate the amide functional group in the given compound: CH_3CH(OH)CH_2NHCOCH_3. The amide group is (NHCO) connecting the amine and the carbonyl groups.

Counting the functional groups

After analyzing the given compound, we have found three distinct functional groups: alcohol, amine, and amide. Ether and carbonyl functional groups are not found in this compound. So, the correct answer is: (B) 3

Key concepts

Alcohol Functional Group

The alcohol functional group is seen quite frequently in organic chemistry and it plays a significant role in both the physical and chemical properties of molecules. Characterized by the presence of a hydroxyl group \textbf{(OH)}, which is simply an oxygen atom bound to a hydrogen atom, it attaches directly to a carbon atom within an organic molecule.

Alcohols can be classified based on the carbon to which the \textbf{(OH)} group is attached — primary (1°), secondary (2°), or tertiary (3°), depending on whether this carbon is connected to one, two, or three other carbon atoms, respectively. For instance, in the step-by-step solution, the compound \textbf{CH\(_3\)CH(OH)CH\(_2\)NHCOCH\(_3\)} features a primary alcohol because the \textbf{(OH)} group is bound to a carbon that is attached to only one other carbon.

Alcohols are polar in nature due to the electronegativity of the oxygen atom, which enables them to engage in hydrogen bonding, drastically influencing their boiling and melting points. This property is crucial for the solubility of alcohol containing compounds in water and for their reactivity, particularly in the formation of hydrogen bonds with other substances.

Amine Functional Group

Amines are another fundamental group in organic chemistry, and they contain the functional group known as the amine group. This group is comprised of a nitrogen atom bonded to one or more alkyl or aryl groups (\textbf{NH\(_x\)}), where \textbf{x} can range from one to three.

In the provided compound, \textbf{CH\(_3\)CH(OH)CH\(_2\)NHCOCH\(_3\)}, the nitrogen of the amine group is attached to a carbon chain, making it an aliphatic amine. Amines are categorized as primary (1°), secondary (2°), or tertiary (3°) based on the number of carbon-containing groups attached to the nitrogen—similar to the classification for alcohols.

Properties of Amines

Amines exhibit basicity due to the lone pair of electrons on the nitrogen that can accept protons. They are also nucleophilic, which means they tend to donate an electron pair to an electron-deficient atom or group within a molecule, making them quite reactive in a wide array of chemical reactions. The polarity of amines varies with their structure, affecting their solubility and boiling points.

Amide Functional Group

Amides stand out in the world of organic chemistry as well, by virtue of their unique structure and properties. An amide functional group consists of a carbonyl group (\textbf{C=O}) connected to a nitrogen atom (\textbf{NH\(_2\)}, \textbf{NH}, or \textbf{N-substituted}).

In the exercise's molecule, the amide group is identified as \textbf{NHCO} which is linking the nitrogen to a carbon atom double-bonded to an oxygen atom. Amides are typically the product of a reaction between a carboxylic acid and an amine or ammonia. This particular functional group can be found in many essential biological substances, such as proteins.

Amide Bond Strength

The amide bond, often referred to as a peptide bond when found in proteins, is known for its resilience, which is due to the resonance stability afforded by the delocalization of electrons between the nitrogen and the oxygen of the carbonyl group. This electron delocalization also contributes to the relatively high melting and boiling points of amides compared to other organic compounds with similar molar masses. Furthermore, this resonance diminishes the basicity of the nitrogen, making amides much less basic than amines.