Draw a Lewis structure for each compound. Include all nonbondi...

Question

Draw a Lewis structure for each compound. Include all nonbonding pairs of electrons.

a. CH₃COCH₂CHCHCOOH

b. NCCH₂COCH₂CHO

Accepted Answer

Hey guys, let's solve this problem. It reads right, the appropriate lewis structure for each of the following compounds. Ch three C O C H C H C 00 H and n C c O c H two C H O. Make sure to include all non bonding electron pairs in your structures. So the first step we have to know how many electrons were going to be adding to our structure. Right. Especially so we can know how many non bonding electron pairs we're going to have. So the first step is to determine the number of valence electrons for your compound, which we do by adding the valence electrons of each atom. Right. And of course we know this comes from the group number on the periodic table. Then once we know how many electrons we're working with, we're gonna sort of draw a rough draft of our structure in sigma bonds form just just all sigma bonds or single bonds. Right. And then once we have those and how many electrons are used to simply connect all of the atoms together, we can then use our remaining number of valence electrons to go back and fill in the missing electrons to complete the octet of the atoms by adding some loan pairs. And you might even create some double bonds. So let's give this a shot with our first compound, which is C H three C O C H C H C O H. Okay, and if you add up all the valence electrons you will get 44 valence electrons. Okay, so step one, check now, the next step we're going to just draw the sigma bond structure. So we'll start from the left, draw that first carbon with three hydrogen or a methyl group. Right? Then we have our next carbon with an oxygen to C H S and C O H. Which if you know car box like acid looks sort of like that. Right, okay, now we have our sigma bonds. And how many electrons did we use to draw those sigma bonds? We used 26 electrons. So that means we have 18 more electrons to add As lone pairs, which would be nine lone pairs, right? nine lone pairs. So let's add those lone pairs to the structure. So which atoms look like they're wanting some electrons. Their octet is not full well all the oxygen's basically. So this oxygen I'm gonna add two lone pairs that looks happy there. I can add three lone pairs here. That makes the octet for the oxygen. Same with this oxygen. And I see that these carbons only have three bonds each so I can really add one to either either carbon and we'll get into fulfilling both of their octet. But I'll just tack it there for now. So that is all of our electrons on the structure. So now let's go in and we'll fine tune it by creating some double bonds. Right? Because not all of our atoms are happy yet. So we have this carbon is good, right? This has four bonds which is eight octet electrons for valence electrons. This carbon only has three signal bonds. So this oxygen can donate those electrons down to create a double bond. Okay then this carbon will be almost happy. Right? Oh no, this carbon will be happy. This carbon is not happy yet. So we need to, it has one extra electron and this carbon is missing one electron for one valence electron. But it still needs two more octet electrons. So this lone pair will also go in between those two carbons and donate. So they satisfy their octet. This oxygen will donate That to that double bond. Just like the first carbon oxygen bond. And like I said, this one is this oxygen is satisfied electrons. So let's redraw our final structure. C H three C double bond. Oh with now two lone pairs, C single bond H double bond, carbon C double bond oxygen again and our last oxygen with two lone pairs, awesome job. You guys, let's move on to our next compound. So we have NCCOCH two CHO. If you add up all these valence electrons, you will get 36 valence electrons. Okay, let's draw it out. So we have our nitrogen carbon carbon, oxygen, Carbon with two hydrogen is coming off of it in our last carbon with an O N H. Okay, so this used up electrons to draw those sigma bonds and I can do more. So again, nine more lone pairs can go on the structure. So let's add those lone pairs. I see. I'm gonna do the similar thing. You're gonna notice. Kind of a pattern with these oxygen's. Right? So we have 2468, electrons. So I have three more lone pairs. I see that this nitrogen carbon area is lacking some electrons. Hm I'm gonna add Just all three lone pairs to the nitrogen for now. Um let's see, I guess to get a little closer to octet, I'll add two to the nitrogen one to the carbon. Okay, so technically the carbon has its valence electrons but not octet. And nitrogen also technically has its valence electrons but not octet. So now that we've added the electrons, we will fix that octet with the double bonds. So in order to make sure the nitrogen and carbon have their octet fill, we can create a triple bond with these two sets of lone pairs coming in between. We can do like we did in the last compound, these oxygen's will donate their lone pair to this carbon that only has three single bonds. And I think that is going to make our compound happy. Let's see what it looks like. C double bond, O c H c h c double bond. Oh, don't forget to add your loan pairs like I almost did. And hydrogen. And do you know what this group is called? The C triple bon en. That is a night trial. Okay. And all of these atoms have their octet fulfilled. So this is my final LeWIS structure for this compound. And that's it for this problem. I hope this is helpful. Thanks for watching.

Draw a Lewis structure for each compound. Include all nonbonding pairs of electrons.
a. CH₃COCH₂CHCHCOOH
b. NCCH₂COCH₂CHO

Key Concepts

Lewis Structures

Valence Electrons

Functional Groups

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