Multiple Choice
Arrange the following fatty acids in order of decreasing solubility in a hexane solution.
I. Myristic Acid II. Stearic Acid III. Lauric Acid IV. Arachidic Acid
507
views
32. Lipids
Physical Properties of Fatty Acids
Multiple Choice
Arrange the following fatty acids in order of increasing melting point.
I. Linolenic Acid (18:3) II. Capric Acid (10:0) III. Erucic Acid (22:1) IV. Cerotic Acid (26:0)
A
IV < I < III < II
B
III < I < IV < II
C
IV < III < II < I
D
I < II < III < IV
Verified step by step guidance1
Understand that the melting point of fatty acids is influenced by the length of the carbon chain and the degree of unsaturation (number of double bonds). Longer chains and fewer double bonds generally lead to higher melting points.
Identify the structure of each fatty acid: Linolenic Acid (18:3) has 18 carbons and 3 double bonds, Capric Acid (10:0) has 10 carbons and no double bonds, Erucic Acid (22:1) has 22 carbons and 1 double bond, and Cerotic Acid (26:0) has 26 carbons and no double bonds.
Compare the degree of unsaturation: Linolenic Acid has the most double bonds (3), which lowers its melting point significantly compared to the others.
Compare the carbon chain lengths: Cerotic Acid has the longest chain (26 carbons), followed by Erucic Acid (22 carbons), Linolenic Acid (18 carbons), and Capric Acid (10 carbons). Longer chains generally have higher melting points.
Arrange the fatty acids in order of increasing melting point by considering both chain length and unsaturation: Linolenic Acid (18:3) < Capric Acid (10:0) < Erucic Acid (22:1) < Cerotic Acid (26:0).
Related Videos
Related Practice
