When molecular iodine, I₂, reacts with an unsaturated compound, one molecule of iodine adds across each double bond - VCE - SSCE Chemistry - Question 19 - 2008 - Paper 1

Given that 0.150 mol of fatty acid reacts with 0.300 mol of iodine, we can derive the number of double bonds. Since each double bond consumes one molecule of iodine, the number of double bonds is given by the equation:

[ \text{Number of double bonds} = \frac{0.300 \text{ mol I₂}}{1} = 0.300 \text{ double bonds} ]

This indicates that the fatty acid has 2 double bonds.

Among the options:

• Lauric acid has 0 double bonds.
• Linoleic acid has 2 double bonds.
• Palmitoleic acid has 1 double bond.
• Arachidonic acid has 4 double bonds.

Thus, the fatty acid that could be is linoleic acid (B).