Molecule proposed lewis structure is this a reasonable...

molecule proposed Lewis structure Is this a reasonable structure? If not, why not? Yes, it's a reasonable structure. : - Cl-0: No, the total number of valence electrons is wrong. CIO$_3$$^-$ The correct number is: :O: No, some atoms have the wrong number of electrons around them. The symbols of the problem atoms are: Yes, it's a reasonable structure. No, the total number of valence electrons is wrong. CO$_2$ :O-C=O: The correct number is: 16 No, some atoms have the wrong number of electrons around them. : .. : Cl: BCl$_3$ The symbols of the problem atoms are: Yes, it's a reasonable structure. No, the total number of valence electrons is wrong. The correct number is: .. Cl-B-Cl: No, some atoms have the wrong number of electrons around them. The symbols of the problem atoms are: * If two or more atoms have the wrong number of valence electrons around them, just enter the chemical symbol for the atom as many times as necessary. For example, if two oxygen atoms have the wrong number of electrons around them, enter the symbol O twice.

Transcript

00:02 There, to analyze each of these structures, we are going to first determine the number of total valence electrons each should have.

00:14 And if those are reasonable or the same as the given structure, then we will sketch the lowest structure ourselves to see if they match up.

00:25 If not, we'll be able to determine where they differ.

00:30 So let's start with the first one.

00:31 First one is b, cl3, boron trichloride.

00:36 Boron's in group 3a of the periodic table, so it has three valence electrons.

00:41 And there are three chlorine.

00:44 Each chlorine has seven valence electrons for a total of 24 valence electrons.

00:54 All right, so let's look at the structure given to us.

00:57 We see that we have 24, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24.

01:03 So the number of valance electrons is correct in the structure given there.

01:09 All right, let's go ahead and draw this structure ourselves.

01:14 We would have boron in the center surrounded by three chlorines, and we know that each chlorine needs at least a single bond to bond it to the boron.

01:25 Then we'll go ahead and start completing optets on each chlorine.

01:33 And we have just used all 24 of our valence electrons.

01:36 We have 24 dots there.

01:40 And what we notice is boron does not have an octet.

01:44 But boron is stable with only six valence electrons.

01:58 In other words, it's an exception to the octet rule.

02:05 Therefore, this structure that we just drew here is the same as the one we see in the structure.

02:13 In the picture there, with the exception of my chlorine on the bottom instead of the top.

02:18 But we know that we're just trying to draw a two -dimensional representation of something that's actually three -dimensional.

02:25 So yes, this is a reasonable structure.

02:33 All right.

02:34 So the structure that we're provided there is reasonable for this, since boron is an exception to the octet rule.