The VSEPR model is a simple predictive tool that is usually,
but ...

Question

The VSEPR model is a simple predictive tool that is usually, but not always, correct. Take urea, for instance, a waste product excreted in animal urine:

What hybridization would you expect for the C and N atoms in urea according to the VSEPR model, and what approximate values would you expect for the various bond angles? What are the actual hybridizations and bond angles based on the molecular model shown? 1Red = O, gray = C, blue = N, ivory = H.2

Accepted Answer

Hello everyone. So this question were given this structure of carbon, ink, acid and we want to go ahead and compare what the hybridization is. If we're using our vesper rule and then the molecular model, we have a legend here that says our gray atom is carbon are white atoms are hydrogen are red atoms are oxygen and our blue atoms are going to be nitrogen. So let's go ahead and first take into consideration arv espero, I'll do vesper and green. Alright, so when taking a look at carbon first. So carbon, like you said from the legend is going to be great. It's this one right here, just right in the middle. So carbon has three bonding groups, right? But you have 12 and three actually write this as well. Three bonding groups that simplify bonding groups as B. G. Because there's three different bonding groups, it's going to be S P two hybridized. Therefore the angle for sp two hybridization according to vesper is going to be equal to 1 20 degrees. So carbon will have an angle of 1 20 degrees. So it's kind of an answer here and now taking into consideration or evaluating our nitrogen atom. Then nitrogen again, according to our legend is going to be in blue. So this right here. So nitrogen has three bonding groups and one lone pair because it has four electron groups total, it is sp three hybridized and according to vesper, the bond angle for that then will be equal to 109. degrees. So according to vesper that nitrogen will have a bond angle of 109.5 degrees. Again, we're just using the vesper model here, not taking into consideration our molecular model then, which I will do in purple. We're taking a look at what we actually see in this structure provided. So for carbon then we said the authority sp two sp two will have a bond angle of 1 20. Now for our nitrogen we don't see a lone pair in the studio structure. So we'll just take into consideration the three different bonding groups which will make the hybridization sp two which then will have a 20 bond angle same as our carbon. So taking a look at the answer choices between 8 30. The only one that also agrees with our um answers that we wrote earlier in our highlighted answers above, which is right over here between the molecular model versus the vesper model predictions. We can see that answer choice C. Is the only one that fits what we have predicted. It's saying that the vessel model is saying that our carbon is sp two hybridized and his sponsor has an angle of 1 20. Nitrogen is sp three hybridized and spawns have an angle of 109.5. But for the molecular model, both carbon and nitrogen are sp two hybridized as well as having an angle of 1 20 degrees. And that's what we said in our predictions earlier on top So statement C. Is going to be my final answer for this problem.

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