Question

Name the type of organic compound from each description of the functional group: (a) polar group that has only single bonds and does not include \(\mathrm{O}\) or \(\mathrm{N} ;\) (b) group that is polar and has a triple bond; (c) group that has single and double bonds and is acidic in water; (d) group that has a double bond and must be at the end of a C chain.

Short answer

(a) Haloalkane, (b) Alkyne, (c) Carboxylic acid, (d) Aldehyde.

Step-by-step solution

Identify Functional Group for Part (a)

The problem specifies a polar group with only single bonds and excludes oxygen and nitrogen. The functional group that fits this description is the haloalkane (alkyl halide), which has carbon single-bonded to a halogen (F, Cl, Br, I).

Identify Functional Group for Part (b)

The problem specifies a polar group with a triple bond. The group fitting this description is the alkyne, which has a carbon-carbon triple bond.

Identify Functional Group for Part (c)

The problem specifies a group with single and double bonds that is acidic in water. Carboxylic acids fit this description, as they contain a carbonyl (C=O) and a hydroxyl (O-H) group, making them acidic.

Identify Functional Group for Part (d)

The problem specifies a group with a double bond at the end of a carbon chain. The aldehyde functional group fits, as it has a carbonyl group bonded to at least one hydrogen atom and resides at the end of the carbon chain.

Key concepts

haloalkane

Haloalkanes (also known as alkyl halides) are organic compounds where a halogen (fluorine, chlorine, bromine, or iodine) is bonded to a carbon atom. Haloalkanes are considered polar because the halogen atoms are more electronegative than carbon, drawing electron density towards themselves.

Key Points about Haloalkanes:

• They contain only single bonds.
• They do not include oxygen or nitrogen atoms.
• Common uses include solvents, refrigerants, and in the production of pharmaceuticals.
• They can undergo nucleophilic substitution and elimination reactions.

Understanding the structure and reactivity of haloalkanes is crucial in organic chemistry.

Haloalkane example: CH₃-Cl (Chloromethane) is a simple haloalkane.

alkyne

Alkynes are organic compounds characterized by carbon-carbon triple bonds. They are part of the hydrocarbon family and are known for their reactivity.

Key Points about Alkynes:

• The triple bond consists of one sigma bond and two pi bonds.
• Alkynes are unsaturated hydrocarbons, meaning they have fewer hydrogen atoms than alkanes and alkenes.
• The simplest alkyne is ethyne (commonly known as acetylene), with the formula C₂H₂.
• Alkynes can participate in addition reactions due to the presence of the reactive triple bond.
• They have linear geometry around the triple bond, giving them a straight-line shape.

Familiarity with alkynes is essential for understanding organic synthesis and chemical reactivity.

Alkyne example: C₂H₂ (Ethyne/Acetylene) is the simplest alkyne.

carboxylic acid

Carboxylic acids are organic compounds containing a carboxyl group (--COOH). This group is made up of a carbonyl group (C=O) and a hydroxyl group (O-H).

Key Points about Carboxylic Acids:

• They are known for their acidity because the hydrogen in the --COOH group can ionize to form H⁺.
• Carboxylic acids can form hydrogen bonds, leading to higher boiling points and solubility in water.
• Common carboxylic acids include acetic acid (found in vinegar) and citric acid (found in citrus fruits).
• They play a vital role in biochemical processes, such as the citric acid cycle.
• Carboxylic acids can be synthesized through oxidation of alcohols and aldehydes.

Understanding carboxylic acids is key to grasping many biological and chemical processes.

Carboxylic Acid example: CH₃COOH (Acetic Acid) is a widely known carboxylic acid.

aldehyde

Aldehydes are organic compounds containing a carbonyl group (C=O) bonded to at least one hydrogen atom. This positioning makes them highly reactive.

Key Points about Aldehydes:

• The carbonyl group in aldehydes is always located at the end of the carbon chain.
• Aldehydes tend to have distinctive, often pleasant, odors.
• They are polar and can participate in hydrogen bonding due to the presence of the carbonyl group.
• Common examples include formaldehyde (used in preserving biological specimens) and benzaldehyde (smells like almonds).
• Aldehydes are intermediates in many organic synthesis reactions, including the production of alcohols and acids.

Understanding aldehydes is essential for studying organic reactions and chemical syntheses.

Aldehyde example: CH₂O (Formaldehyde) is a simple and well-known aldehyde.