Here in this example question, it says within each pair, determine the fatty acid with a greater melting point. Now remember, if we increase our number of carbons, then that's going to cause an increase in my melting point. And if I increase my number of pi bonds, that's going to cause a decrease in my melting point. If we take a look here at our 2 fatty acids, we have Stearic Acid with 18 carbons, Oleic Acid with 18 carbons, so we can't rely on the number of carbons. What we rely on instead is the number of Pi Bonds. Stearic Acid has 0 Pi bonds, Oleic Acid has 1. Remember, increasing the number of pi bonds decreases my melting point. So, Stearic Acid would be higher in terms of melting point.

Next, we have Linolenic acid, which has 18 carbons and 3 pi bonds. And we have here, Met acid, which has 23 carbons. So both of them have the same number of pi bonds, but they have a different number of carbons. Since this has more carbons, it'll have a higher melting point. Next, we have 18 carbons and 1 pi bond, 16 carbons and 1 pi bond. Again, the number of pi bonds are the same, but this one here has more carbons, so it's going to have a higher melting point.

And then finally, we have 18 carbons and 4 Pi bonds, 20 carbons and 3 Pi bonds. There are 2 forces at work here. First, our second fatty acid has more carbons which should result in a higher melting point and in addition to this, it has fewer pi bonds, it has one less pi bond which would also cause an increase in my melting point. So for those two reasons, this fatty acid would have a higher melting point.

So, these are the different fatty acids based on each pair that would have the greater melting point.