What is the largest pigment molecule?

• A. Titanium dioxide
• B. Iron oxide
• C. Carbon
• D. Organic pigments

Answer: (A)

In pigment chemistry, molecular size tracks with structural complexity. Organic pigments are built from large carbon-based molecules with lengthy chains or fused-ring systems, giving high molecular weight and a lot of structural detail. Inorganic pigments like titanium dioxide are simple compounds (TiO2) that form crystal lattices—their fundamental units are small and repetitive rather than large molecules. Iron oxides are mineral pigments with relatively compact formulas, and carbon pigments are essentially aggregates of carbon particles rather than single large molecules. Because of these differences, the largest pigment molecule among common types is an organic pigment.