Write the formulas of the three doubly brominated isomers form...

Question

Write the formulas of the three doubly brominated isomers formed when 2-methylpropane reacts with Br₂ in the presence of light.

Accepted Answer

Hi, everybody. Our next question says, what are the structures of the two doubly brominated isomers produced by the light induced reaction of 2233 tetra methyl butane with BR two, we have a structure of our molecule here plus BR two. And we need to, to determine what the two possible isomers would be knowing that it's doubly brominated, there's two bromine atoms that will go on here. So are structures drawn with all of the hydrogens and carbons written in specifically. But it's a little easier to see with the skeletal structure where those brom means can possibly go. So I'm going to draw our molecules of skeletal structure, these two central carbons, each with three methyl groups coming off. So when we think about where bromine can possibly go here, we know that it cannot go on to these two central carbons because they each have four bonds, they have a bond to each other. And then three methyl groups, our bromine can go on to one of the methyl groups on say one side. But let's recall, this is a tetrahedral uh structure of the bond here. This carbon has four bonds. And so this is a symmetrical arrangement. So any of these bromine and excuse me, any of these methyl groups that the bromine attaches to. So if I draw my structure, for instance, with the bro, I drew it on the burns's top methyl group. If I add this bromine to the middle methyl group, this is the same molecule because these, we recall in our tetrahedral structure, imagine our carbon here and I've drawn a carbon with four bonds coming off of it. In this case, we would have another carbon. And then our methyl groups, this will all be a symmetrical molecule, all of these bonds at 109 degree angles from each other. So a bromine added to any one of these will result in the identical molecule. And that will be the case on either side. And we know we have two brom means it's going to erase the second one I drew since I know it will be identical. So then the only two possible arrangements are one bromine added to either side of our molecule. So a bromine on a methyl group, one on either side or the arrangement where the BROM means are added on the same side of the molecule. So we'll draw that in again, it doesn't matter which metal group they're added to due to the symmetrical nature of the tetrahedral bonding. So there are only two as, as our question says, there are only two possible isomers. It wants us to draw the structures. And our structure was given to us with the carbons and hydrogens specifically indicated. So I've drawn two um skeletal structures. But if I want to give the answer in the same format, I was given the reactant are two possible isomers with hydrogens and carbons. So our first one or two carbons, each one has three carbons bonded to it. The three methyl groups in our first structure, we have a bromine on either side. So I'm just going to add the bromine to the top Carmen and it still has two hydrogens bonded to it. All the others have three hydrogens. So we have bromine and H two cch three ch three. And then on the other side, add a bromine to the top carbon. It still has two hydrogens and then add three hydrogens to the other carbons. Our central carbons have no hydrogens because they have four bonds to them. So that's isomer. Number one, I'll put or and isomer number two. Again, we draw the similar two carbons in the center with no hydrogens. Each one having a bond to three more carbons. In this case, our bromine will both be on the same side. So we'll add them to the first two carbons. And each of these still has two hydrogens on them, three hydrogens on the third carbon. And then on the other side, there will be three hydrogens on each carbon. So there are two possible isomers one with the BROM means on either side of the molecule, one with the BROM means on the same side, see you in the next video.

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Write the formulas of the three doubly brominated isomers formed when 2-methylpropane reacts with Br₂ in the presence of light.

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