In the synthesis of the paint resin Glyptal, phthalic acid is utilized as a monomer. What is the tot — Polymers Chemistry Question

💡 Solution & Explanation

Phthalic acid is benzene-1,2-dicarboxylic acid. The benzene ring consists of 6 carbon atoms, all of which are $sp^2$ hybridized. The two carbon atoms in the two carboxylic acid ($-COOH$) groups are also part of a $C=O$ double bond and are therefore $sp^2$ hybridized. Total $sp^2$ carbons = $6 + 2 = 8$.