Q.Give condensed and bond-line structural formulas and identify the functional group(s) present, if any, for:

Concept: Structural Representation and Functional Groups

The IUPAC name encodes the carbon skeleton, substituents, and functional groups. The condensed formula shows atom connectivity compactly; the bond-line (skeletal) formula depicts carbon chains as zig-zag lines with heteroatoms labeled explicitly.

(a) 2,2,4-Trimethylpentane

The parent chain is pentane (5 carbons). Methyl groups are at C-2 (two) and C-4 (one).

Condensed formula:

Bond-line formula:

Functional group: None (saturated hydrocarbon, alkane).

(b) 2-Hydroxy-1,2,3-propanetricarboxylic acid

A three-carbon chain with carboxylic acid groups at C-1, C-2, C-3, and a hydroxyl at C-2. This is citric acid.

Condensed formula:

Bond-line formula:

Functional groups: Carboxylic acid ($-\text{COOH}$, three), hydroxyl ($-\text{OH}$, one).

(c) Hexanedial

A six-carbon chain with aldehyde groups at both ends. …

Decode each IUPAC name into its carbon skeleton, write the condensed formula, sketch the bond-line (skeletal) form, and read off the functional groups.

(a) 2,2,4-Trimethylpentane

A five-carbon (pentane) main chain carrying two methyl branches on C-2 and one on C-4.

Condensed formula: $\text{(CH}_3)_3\text{C--CH}_2\text{--CH(CH}_3)\text{--CH}_3$

Bond-line: a five-carbon zig-zag; two extra bonds meet at the second carbon (a quaternary carbon) and one extra bond at the fourth carbon. Every vertex and chain end is a carbon, hydrogens implicit.

Functional group: none — it is a saturated hydrocarbon (alkane).

(b) 2-Hydroxy-1,2,3-propanetricarboxylic acid

A three-carbon (propane) backbone bearing a $\text{--COOH}$ on each of C-1, C-2 and C-3 and an $\text{--OH}$ on C-2. This is citric acid.

Condensed formula: $\text{HOOC--CH}_2\text{--C(OH)(COOH)--CH}_2\text{--COOH}$

Bond-line: the central carbon carries an $\text{--OH}$ and a $\text{--COOH}$; each of the two arms is a $\text{--CH}_2\text{--COOH}$, the carboxyls drawn as $\text{CO}_2\text{H}$.

Functional groups: three carboxylic-acid ($\text{--COOH}$) groups and one alcohol ($\text{--OH}$).

(c) Hexanedial

A six-carbon (hexane) chain with an aldehyde ($\text{--CHO}$) at each end (the "-dial" suffix; aldehydes must be terminal).

Condensed formula: $\text{OHC--(CH}_2)_4\text{--CHO}$

Bond-line: a six-carbon zig-zag with a carbonyl ($=\!\text{O}$) at each terminal carbon. …