Classify each reaction as an oxidation, a reduction, or neithe...

Question

Classify each reaction as an oxidation, a reduction, or neither.

(g)

(h)

(i)

Accepted Answer

Hey everyone and welcome back in today's video, we are going to label each of the following reactions as reduction, oxidation or none of it. Now. Whenever we are thinking about the problem of that kind, we have three different reactions A B N. C. And we have to recall what an oxidation reduction reaction is an oxidation reaction. An oxidation reduction reaction, My apologies or a redox reaction essentially involves a transfer of electrons. Right? So the oxidation state of our elements essentially changes in organic chemistry. It is easier to think about this concept from a slightly different perspective in terms of addition or removal of hydrogen and oxygen atoms. So let's create general guidelines for us. Let's suppose that we want to think about an oxidation reaction. What are the possibilities for that? So, an oxidation reaction essentially would imply addition of oxygen or die atomic oxygen as well as addition of X. C where X is a halogen. Right? And then also from another perspective, we can think about oxidation as a loss of hydrogen Age two now. Similarly, if we think about reduction, reduction, reduction can be identified by the addition of age two. Hi tried H minus as well as loss of oxygen or that atomic oxygen and also loss of halogen X. T where X is a halogen di atomic halogen. So this is how we can visualize reduction. And similarly, let's look at several examples where we have neither of them. So those examples would include addition or loss of H plus. So that would be aged plus each two. That would be water, H X, which represents hydrogen. Hey, light and so on. So whenever we are dealing with these, whether it's additional lost doesn't matter. That's generally neither. So let's use these guidelines to answer the question to our problem. In the first reaction we have an addition of hydrogen bromide. Right? This is our hydrogen hay light. The reason why we have an addition because you may notice how the pi bond is broken. On one end of the the original pi bond we have hydrogen added and on the other end we have roaming added. So this is a typical electra Filic edition reaction where we are breaking the pi bond and adding hydrogen. Hey light based on the more comical school we call that we said that additional loss of hygiene. Hey light represents neither oxidation nor reduction. So we can say that the answer to the first one is neither. Okay, so this reaction is neither oxidation nor reduction. Now let's look at B. We have two reactions actually. And in the first reaction we have an alcohol which produces an L keen. We're using sulfuric acid which represents an acid catalyzed dehydration of alcohols. And this is actually implied by this minus H two. We have a loss of water rights so that be hygiene. We have removed it and we all also removed O. H. So overall you can think about this as loss of water and we previously said that neither also involves addition or loss of water. So this works for us, right? We have a loss of water, so a loss of water represents neither oxidation nor reduction again. However, we have our second reaction where the double bond here, our pi bond is essentially broken. Right? We are adding two hydrogen atoms. Notice how in the original alki and we only have two hydrogen atoms because each carbon atom must have four bonds and finally to have four bonds here, we must have two hydrogen on each carbon. And we simply are adding a molecule of H two. Right, remember that addition of hydrogen H two. And this is what we are observing. This is a platinum catalyzed hydrogenation of an elk in right, so we see that we have an addition of age too because we're adding two hydrogen atoms across our double bond, we're breaking the pi bond in addition of hydrogen essentially implies that this is reduction. So let's label the second reaction as reduction of course. Remember that we have two steps here. This is our step number one and this is our step number two. So step number one is nighter and step number two is reduction. And finally, let's think about C for C, we have our starting al keen, it produces a sin dial. The two alcohol groups are added in sin arrangement using osmium tetroxide which is a source of oxygen atoms followed by hygiene peroxide, which essentially allows us to produce the final alcohol groups essentially this reaction would be an oxidation reaction because we have addition of oxygen, notice how each carbon atom it now has oxygen added to it, and then hydrogen atoms come from the work up with hydrogen peroxide. But in the first step, whenever we are adding these two oxygen atoms, we essentially add them from osmium tetroxide. An addition of oxygen is an oxidation reaction so we can label C as oxidation. We are done. Let's label our final answers. We have our answers to A. B and C. So for a it's neither oxidation or reduction. For B, we have two answers. Step number one is neither of them, but step number two corresponds to reduction and for see the reaction corresponds to an oxidation reaction. And based on these answers, we may conclude that the correct answer to the multiple choice question is d However, if you have any questions, don't hesitate to leave your comment down below and thank you for watching

Classify each reaction as an oxidation, a reduction, or neither.
(g)
(h)
(i)

Key Concepts

Oxidation and Reduction

Electrophilic Addition Reactions

Hydrogenation

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