For each of the reactions in Problem 15, indicate which reacta...

Question

For each of the reactions in Problem 15, indicate which reactant is the nucleophile and which is the electrophile.

a. Curved arrows illustrate electron movement in a chemical reaction involving hydroxide and water molecules.

b. Curved arrows illustrate electron movement in a reaction between a benzene ring and a bromine ion.

Accepted Answer

Hey, everyone. And welcome back in today's video. We're going to solve the following problem in each of the following reactions indicate the electro file and the nuclear file. Before we begin, let's remember what the electro files and nuclear files are. Electro files generally labeled as E plus and nuclear files and you minus their specific species which are involved in organic chemistry reactions. Electro files are defined as electron pair except ear's when a Candyland bond is formed and nuclear files are electron pair donors. So if you look at this problem specifically, in part, a, we have our reaction between formic asset and hydro knee um to produce the protein ated form of the acid and water. So what is the difference between our reactant and products if we look at hydro ni um it basically loses one of its hydrogen, right? We're producing H T O. And it's very important to understand that oxygen now has two lone pairs instead of one. Now our curb oxalic acid, initially at the Carbondale group, we had two lone pairs at oxygen and now we only see one. And in addition, we have oxygen hydrogen bond formed. So what we're doing is just taking the lone pair of oxygen and using that lone pair in the formation of that oxygen hydrogen bond, right. So that's what we're actually performing. So let's draw it clearly, Right? So, notice that this lone parent oxygen is used in the formation of OH one. And then because there's that additional lone parent oxygen and water were actually transferring oxygen hydrogen electrons in the form of a lone parent oxygen. So, this hygiene specifically is our electro file because it doesn't use any of its electrons in the bond formation and it's basically accepting the electrons from oxygen. Therefore, we can say that Hydro knee um or specifically this hydrant from hydro ni um is our electro file and our asset is the new club file because it uses its long pair electrons from Carbondale group, specifically oxygen to create that O H bond, right. It's an electron pair donor hygienists and electron pair except er final result, we are creating an O H bond and we are producing a water molecule where the two electrons from an O H bond have been transferred onto oxygen. Now, let's look at part B, we have our starting material which is an elk in and which reacts with ammonium Caroline because we have a positive charge on roaming okay. So blooming has three lone pairs in the product formed, we still have these three lone pairs of grooming, right. So it basically means that this bond that has been created between carbon and grooming involves electrons that actually belong to carbon. Right? In other words, if you still see exactly the same number of lone pairs on, bro mean it must be that electron pair except er still three original lone pairs in Rome. In that means that it must be an electro file. And in addition to that is positively charged, the electro files tend to be possibly charged or at least partially positively charged. So this is our electro file and our elkin must be the nuclear file. Let's understand why. It's basically because the alc in has our pi bond, there's a high electron density and notice how we are breaking that pi bond there somewhere pi bond in the final structure. So these two electrons from the pi bond are used in the formation of that carbon booming bond. And these two electrons now appear within that sigma bond right between carbon and blooming. So these are our electrons. And that means that our al king is actually the nuclear file because it's an electron pair donor. In addition to that, because we're breaking our pipe on notice that we're getting a positive charge at the adjacent carbon because originally it has four bonds. Now it has three. So four minus three gives us a formal positive charge, right? Essentially, this carbon is electron deficient. That's why we have that positive charge. But other than that, once again, roaming accepts an electron pair because it still has the three lone pairs and it forms a bond. So it must be our electro file and our al king donates electrons because we're breaking the pi bond and forming our sigma bond between carbon and booming out of that pi bond. So it must be our nuclear file, right, electron pair donor. So let's label our final answers for a our asset as the nuclear file. Hydro knee um is the electro file and for B D Elkin is our nuclear file and the Ammonium Karen is our electro file based on these answers. The correct answer to the multiple choice question is B Thank you for watching.

For each of the reactions in Problem 15, indicate which reactant is the nucleophile and which is the electrophile.
a.
b.

Key Concepts

Nucleophile

Electrophile

Reaction Mechanism

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