The total number of 'sigma' and 'Pi' bonds in 2-oxohex-4-ynoic acid is ____.
Answer: 18
Solution
2-Oxohex-4-ynoic acid: HOOC−CO−CH2−C≡C−CH3. Counting bonds: the −COOH group has 1 C=O (σ+π) and 1 C–OH σ; the keto C=O contributes 1 more σ+π; the CH2 and CH3 carbons and their C–H/C–C bonds are all σ; the C≡C triple bond contributes 1 σ and 2 π. Totaling all bonds in the structure gives 14 σ bonds and 4 π bonds (2 from the two C=O groups, 2 from the C≡C triple bond):
