Final answer:
A 16 carbon saturated fatty acid is heavier than a 16 carbon unsaturated fatty acid because it contains more hydrogen atoms; this is because the carbon atoms in saturated fats are bonded to the maximum number of hydrogen atoms, unlike in unsaturated fats where there are double bonds between some carbon atoms resulting to fewer hydrogen bonds.
Step-by-step explanation:
A 16 carbon saturated fatty acid has a higher molecular weight than a 16 carbon unsaturated fatty acid because it has more hydrogen atoms. In saturated fatty acids, each carbon atom is bonded to the maximum number of hydrogen atoms possible, hence the term 'saturated'. In contrast, unsaturated fatty acids contain one or more double bonds between some of the carbon atoms, reducing the number of hydrogen atoms that can bond with the carbon atoms. Since the weight of a molecule is determined by the total weight of all its atoms, a molecule with more hydrogen atoms has a greater molecular weight.
Learn more about Saturated and Unsaturated Fatty Acids