Question

What is the sum of number of ɑ and π bonds present in 2-oxo-hex-4-yne-oic acid ?

Answer 1

Correct Answer: 18

To determine the sum of sigma (σ) and pi (π) bonds in 2-oxo-hex-4-yne-oic acid, we start by understanding its structure:

• Carbon Backbone: The name indicates a 6-carbon chain (hex).
• 2-oxo: A keto group (C=O) at the second carbon adds 1 σ and 1 π bond.
• 4-yne: A triple bond between carbons 4 and 5 includes 1 σ and 2 π bonds.
• -oic acid: A carboxylic acid (COOH) group on the terminal carbon (C-1) adds a C=O bond (1 σ and 1 π) plus 2 C-OH single bonds (each with 1 σ bond).

Now, we count each type of bond in the molecule:

• C-C bonds: 5 single bonds between continuous carbon atoms, each with 1 σ bond, contributing 5 σ bonds.
• C=O in -COOH: 1 σ and 1 π bond.
• 2-Oxo ketone group: 1 σ and 1 π bond from C=O.
• Triple bond (C≡C): 1 σ and 2 π bonds.
• C-OH in -COOH: 2 σ bonds (1 for each C-O bond).

Summing these gives:

• σ bonds: 5 (C-C) + 1 (C=O, oxo-group) + 1 (C-O) + 2 (C-OH) = 9 σ bonds.
• π bonds: 1 (C=O, oxo-group) + 2 (triple bond) + 1 (C=O in -COOH) = 4 π bonds.

Total bonds (σ + π) = 9 + 4 = 13.

This computed total of 13 doesn't match the initially suggested range of 18,18. Re-examining the given structure and components confirms our total as accurate based on the described molecular formula and naming.