Among the following hydrocarbons, which one is the most acidic? — Aromatic Hydrocarbons Chemistry Question

💡 Solution & Explanation

The acidity of a hydrocarbon depends on the stability of its conjugate base. When cyclopentadiene loses a proton ($H^+$), it forms the cyclopentadienyl anion. This anion is planar, cyclic, completely conjugated, and has $6\pi$ electrons, making it highly stable due to aromaticity. Thus, cyclopentadiene is unusually acidic for a hydrocarbon.