Ethyl acetate mathrmc4 mathrmh8 mathrmo2 is a fragrant...

Ethyl acetate, $\mathrm{C}_{4} \mathrm{H}_{8} \mathrm{O}_{2},$ is a fragrant substance used both as a solvent and as an aroma enhancer. Its Lewis structure is (a) What is the hybridization at each of the carbon atoms of the molecule? (b) What is the total number of valence electrons in ethyl acetate? (c) How many of the valence electrons are used to make $\sigma$ bonds in the molecule? (d) How many valence electrons are used to make $\pi$ bonds? (e) How many valence electrons remain in nonbonding pairs in the molecule?

Transcript

00:01 Okay, so the formula for ethylacetate is c4h8o2.

00:09 And so when we build ethylacetate, we're going to have a carbon, and that's going to wind up being attached to another carbon, double bonded to an o, single bonded to an o, with two more carbons, and h.

00:40 Filling out the rest of the spaces.

00:47 So this is ethylacetate.

00:49 You can see we have our one, two, three, four carbons, one, two, three, four, five, six, seven, eight hydrogens, two oxygens.

00:59 And we're gonna try to figure a few things out about this.

01:05 And so if we wanna know about hybridization, we're gonna want to deal with the number of electron domains or electron regions there are.

01:20 The number of places where we have electrons, whether they are bonded or lone pairs, doesn't matter.

01:28 And so we're gonna do it for each of the carbons.

01:31 So let me just call this one, carbon one, carbon two, three, and four.

01:37 Okay, so for carbon one, you can see that there are four different places where we have bonds.

01:48 And so the four domains gives us an sp3 hybridization.

02:01 So if you think about having a one by the s, we don't write the one, but if you think about the one, one plus three is four domains.

02:12 This carbon, there's only three places where there are bonds, west, east, and north.

02:19 This double bond does not count as two domains.

02:22 So there's three domains, which makes it sp2, 1 plus 2, 3 domains.

02:33 If we take a look at 3, there are four distinct places, north, south, east, and west, where we have electrons, four domains, which makes it sp3, and the same thing for the fourth one.

02:50 There are four places where we have electrons, so that makes it sp3.

02:57 Now, what are the total number of valence electrons? well, let's take a look at how many valence electrons there are for each of these elements.

03:11 Carbon has four valence electrons.

03:15 So we have four atoms times four valence electrons.

03:23 That's 16 electrons.

03:28 If we take a look at the hydrogen that has one valence electron, but we have eight atoms.

03:34 So multiply that by our one valence electron, that's eight valence electrons.

03:41 Oxygen has six valence electrons, and there are two atoms of it.

03:52 So that is 12 electrons...