In this video on trio glycerol reactions, we take a look at hydrogenation. Now, recall that under this type of reaction, we're gonna have two hydrogens being added to one py bomb. And we say here that the conversion from double bonds to single bonds will help to decrease un saturation as we lose our pie bonds. And this will cause an increase in my melting point. When we take a look at hydrogenation reactions realize that there was complete hydrogenation where all of our carbon double bond, carbon bonds are reduced to single bonds. And then we also have partial hydrogenation when some but not all carbon carbon double bonds are reduced to single bonds. Now, if we take a look here at the complete one we have here, our triglyceride molecule or I tri ayl glycerol molecule and we're gonna say here, trine is its name. And here if we look at our products, we can see that all three double bonds have been removed. And now we have just single bonded fatty acid chains here. Remember when it comes to hydrogenation, we use H two with some type of metal catalyst. Here, nickel is a common type of metal catalyst that is used. Also remember that when it comes to hydrogenation, one mole of H two is required for every single pi bond that we have because there are three pi bonds that were erased and are no longer part of my product. That means I used three moles of H two to do this complete hydrogenation. Now again, with partial hydrogenation, some but not all carbon double bonded carbon bonds are reduced to single bonds. Here, we start out with three and at the end, we only have one left, two of them were removed, they were reduced. So, since two pi bonds were removed, that would mean that we needed two moles of H two. And we still use our nickel catalyst. Now, what's the whole point of doing partial hydrogenation? Why not go all the way and reduce all the pi bonds to single bonds? Well, we're gonna say that this is commercially manufactured. We're gonna say here that partial hydrogenation converts oils to different types of margarines. And ultimate consistency is based on the number of py bonds. So companies will make these partially hydrogenated oils in order to make different types of margarines, we can actually affect the hardness of these margarines because there's soft margarines versus hard margarines based on a number of pi bonds remaining in our product, right? So normally we do complete hydrogenation, but some companies are able to only do partial hydrogenation where they wanna create margarines from oils. Right. So just keep this in mind hydrogenation that it can be complete or can be partial.
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example
Triacylglycerol Reactions: Hydrogenation Example 1
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Video transcript
In this example question, it says, identify the number of moles of hydrogen required for the complete hydrogenation of the following compound. So remember, complete hydrogenation means we need to get rid of all the carbon double bonded carbon bonds within our triglyceride molecule. If we take a look here, we see that we have 12, 345 total carbon double bodied carbon bonds within our triglyceride molecule or our trio glycerol molecule. Because there's five of them that would mean that we require five moles of H two. And again, we'd use some type of metal catalysts to help make this go faster. Nickel is a good example, you can also do platinum or palladium as well. So again, there's five pi bonds within this triglyceride. So that requires five moles of H two for the complete hydrogenation of this triglyceride molecule.
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Problem
Problem
Determine a possible triacylglycerol molecule formed when linoleic acid undergoes partial hydrogenation and consumes 1 mole of hydrogen gas.
A
Palmitoleic acid
B
Stearic acid
C
Linolenic acid
D
Oleic acid
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Problem
Problem
Assuming a complete reaction with hydrogen gas, which of the following molecules would have the greatest increase in melting point?
A
B
C
D
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