Determine the geometry about each interior atom in each molecule and sketch the molecule. (Skeletal structure is indicated in parentheses.) b. CH₃OCH₃ (H₃COCH₃)

Video transcript

Hey everyone today, we've been giving the chemical formula and skeletal structure of a compound and are being asked to draw that Lewis structure and identify the geometry for each of the internal atoms of the compound. Now first off, let's draw out the LewiS structure. And the very first step to doing this is identifying how many valence electrons we have. So carbon is a group four element, Group four element, which means it will have four valence electrons. And we have three carbons right there, Hydrogen is the very first element. It's in group one has one valence electron, We have eight of those. Finally, oxygen is in group six has six valence electrons. And we only have one of those. So let's add that up. That brings us to 12 plus eight plus six. She calls What 26 valence electrons. Before drawing the LewiS structure. Let's really quickly look at the skeletal structure. So this means that we have C. H. Two Bonded to Ch three. And to this central carbon, you'll also be bonded to this oxygen which again is intern Bonded to the CH three. The metal group. So let's write that out. We'll start with the CH two, H and H. It will be attached to a metal group that's um ethel M. E. T. H. Y. E. L. Attached to an oxygen. Which will itself be attached to another metal group. H H. H. That's so far in a molecule we have eight ah 14 and 22. We only have 22 valence electrons. So we still need four more. This can be added as lone pairs around the oxygen because it was the only one that didn't have a full octet yet. So, our lewis structure of the compound is done. Now let's take a look at the geometry for the internal atoms. These ones here, luckily for us, this can be pretty simple. The carbons all have the same geometry. And this is because if we look at it, we can see they each have four bonds, right? They have four bonds, but they have zero loan pairs, zero lone pairs. Because of this, when you draw them or when they exist in space like this, they will have a tetra. He'd real structure looking sort of like a plus sign. It'll be plainer. It won't poke out at any weird angles. It'll just be tetrahedron four directions. Meanwhile, the oxygen, however, has a slightly different tune. You see? It has two lone pairs, right? So oxygen has two bonds, these two bones right here, two bonds And two lone pairs. So because of this, the lone pairs will actually rearrange themselves and cause a sort of repulsion effect on the other bonds that exist there. So, we'll end up with a bent geometry. This will have a bent geometry. Therefore, for the carbons in this molecule, we'll have a tetrahedron geometry and the oxygen will have a bent geometry. I hope this helps. And I look forward to seeing you in the next one