Determine whether the following pairs of structures are actually ...

Question

Determine whether the following pairs of structures are actually different compounds or simply resonance forms of the same compounds. e.

and

f.

and

g. [CH2=CHCH2]+

and [CH2CH=CH2]+

h. CH2=C=O

and HC≡COH

Accepted Answer

Hey everyone, Let's solve this problem. It says some pairs of structures are given at the end of the question. Recognize each of these pairs as different entities or resonance forms of the same compound, interesting questions. So what makes compounds resonance forms? Well, they have the same atoms right. Same number of state carbons, hydrogen, nitrogen is oxygen's so the number of atoms is not changing and the number of type of atom is not changing. The connectivity of the atoms stays the same between resonance structures. So the order that those atoms are connected to one another. So say if I had carbon, oxygen and carbon and then oxygen and carbon, carbon, that's the same number of atoms. But they're connected differently. So that is those are two different structures. But what does change in resonance structures? The only thing that's changing is the location of electrons. So the thing that we're going to keep an eye out for is the connectivity of the atoms. Because that will tell us if they're the same, they're just resonant structures. If they're connected differently, then they will be different atoms. You see what I mean? Let's figure this out. So I'm going to redraw our compounds have a nitrile group. C travel bond and bond attune oxygen. And is this second compound connected differently? No, it's still N. C. O. Just turned around the other way. So I'm going to write it flipped around so now we can compare them and see, okay, we still have one nitrogen carbon oxygen connected in the same order. The only thing that's changing is those electrons from the oxygen are coming down between the carbon and then one of the bonds from the nitro group are coming onto the nitrogen. So in summary, are these different compounds? No, they're just resonance forms, right? Only the electrons are moving. Does that make sense? Let's highlight it resonance forms for part A For part B. We have 25 member rings in a double bond in that ring and there's a carbonell group coming off of one of the carbons. So let's look at the hydrogen on this ring. They're sneaky trying to hide their So remember that any carbon that is not in the double bond or that a single bond has two single bonds rather will have to hydrogen. And the carbons that are in the alpine are going to have one hydrogen. Do you notice anything? Any carbons that have different number of hydrogen on them? Oh yeah, they're sneaky. This carbon has one hydrogen in the first structure and two on the second. And this carbon also has two in the first and now one in the second. So, although we have the same number of atoms right? There's 12345 carbons, 246 hydrogen and one oxygen. So the same number of atoms. But those connectivity, the connectivity is different. So, these are not residents forms. They are different compounds. Okay, different compounds. All right, onto the last one. We have oxygen double bond to carbon and two methyl groups which is acetone. And then we have an ALC in. I'm going to write these out then we have an AL keen and the methyl group and now an alcohol group. Well, this one seems kind of obvious to me. You guys, I don't know about you. But right away I see that this oxygen has no hydrogen and this oxygen has a hydrogen attached to it. So just off of that, I can tell that these are different compounds. Right? It doesn't even matter about double bonds. Where doesn't matter those are different compounds because there's no hydrogen on that oxygen in the first compound. Also, there's two methyl groups in the first compound and now there's a methyl group and this carbon only has two hydrogen. So again, the connectivity of those atoms are changing even though there's the same number of atoms, same number of carbons, hydrogen and oxygen's the connectivity is different. So, they are different compounds. Alright, that's it for this problem. I hope this video is helpful. And thanks for watching

Determine whether the following pairs of structures are actually different compounds or simply resonance forms of the same compounds. e. and f. and g. [CH2=CHCH2]+ and [CH2CH=CH2]+ h. CH2=C=O and HC≡COH

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Determine whether the following pairs of structures are actually different compounds or simply resonance forms of the same compounds. e.
and
f.
and
g. [CH2=CHCH2]+
and [CH2CH=CH2]+
h. CH2=C=O
and HC≡COH