See image — Aromatic Hydrocarbons Chemistry Question

💡 Solution & Explanation

Step 1: Analyze each compound in Column (I) for aromaticity and EAN rule. (a) 2,4,6-Trichloro-1,3,5-triazine (Cyanuric chloride): - This is a six-membered ring with 3 C and 3 N atoms in alternating positions, fully conjugated. - It is planar, cyclic, and has 6 pi electrons (3 double bonds in the ring, each contributing 2 pi electrons = 6 pi electrons). - 6 pi electrons = 4n+2 with n=1, satisfying Huckel's rule. - Therefore it is aromatic (p) and has (4n+2)pi electrons in a single ring (q). - It is not a metal complex, so EAN rule (s) does not apply. - Matches: a -> p, q (b) Borazine (B3N3H6): - This is called 'inorganic benzene'. It is a six-membered ring with alternating B and N atoms, planar and cyclic. - Each N atom donates a lone pair into the pi system. There are 3 N lone pairs contributing 2 electrons each = 6 pi electrons. - 6 pi electrons = 4n+2 with n=1, satisfying Huckel's rule. - Therefore it is aromatic (p) and has (4n+2)pi electrons in a single ring (q). - It is not a metal complex, so EAN rule (s) does not apply. - Matches: b -> p, q (c) Ferrocene Fe(C5H5)2: - Each cyclopentadienyl (Cp) ring C5H5^- is a 6 pi electron aromatic anion (4n+2, n=1). The Cp^- ring has 6 pi electrons and is aromatic (p) and satisfies (4n+2)pi in a single ring (q). - EAN of Fe in ferrocene: Fe is in +2 oxidation state, Fe^2+ has 24 electrons. Each Cp^- donates 6 electrons, two Cp^- donate 12 electrons total. EAN = 24 + 12 = 36 = Kr configuration. So EAN = 36 (s). - Matches: c -> p, q, s (d) Dibenzenechromium Cr(C6H6)2: - Each benzene ring (C6H6) has 6 pi electrons, aromatic (p), satisfies (4n+2)pi in a single ring (q). - EAN of Cr in Cr(C6H6)2: Cr is in 0 oxidation state, Cr has 24 electrons. Each benzene donates 6 electrons, two benzenes donate 12 electrons total. EAN = 24 + 12 = 36 = Kr configuration. So EAN = 36 (s). - Matches: d -> p, q, s Note on option (r): 4n*pi electron in a single ring describes antiaromatic systems. None of the given compounds are antiaromatic, so (r) is not matched to any. Therefore, the correct answer is a-p,q; b-p,q; c-p,q,s; d-p,q,s.