An aromatic hydrocarbon A with molecular formula C ₉ H ₁₂ is oxidized by hot alkaline KMnO ₄ followed by acidification to give a tribasic acid B . Nitration of B with an HNO ₃/ H ₂ SO ₄ mixture yields only a single mononitro derivative C . The total number of -bonds in one molecule of product C is

Step-by-step solution

The formation of a tribasic acid B upon oxidation implies that hydrocarbon A has three oxidizable alkyl side chains. Since A has the formula C ₉ H ₁₂ , it must be a trimethylbenzene. The three isomers of trimethylbenzene are 1,2,3 -trimethylbenzene, 1,2,4 -trimethylbenzene, and 1,3,5 -trimethylbenzene. Upon oxidation, they yield the corresponding benzenetricarboxylic acids. Nitration of B yields only a single mononitro derivative C . This indicates that all available ring positions in B are equivalent by symmetry.