States of matter identifying a molecule from its...

States of Matter Identifying a molecule from its electrostatic potential map This sketch of a neutral molecule is shaded red or blue wherever the electrostatic potential at the molecule's surface isn't zero. What could the chemical formula of the molecule be? electrostatic potential map possible chemical formula (check all that apply) $COCl_2$ $HCN$ $SO_3$ $C_2H_2$ $N_2H_2$

Transcript

00:01 Okay, so we have this molecule represented by an electrostatic potential map, meaning areas where the partial charges are non -zero are shaded.

00:10 So you have red in the middle.

00:11 This means that there's a net plus charge here, and then this blue on the ends means there's a net negative charge.

00:18 So we would assume that this molecule has some kind of central atom, which we'll call x, and then two regions around it.

00:28 So it looks like a linear molecule where the outer atom has more electron, more electronegativity and is pulling the electrons this way.

00:41 So then we can check off all that are consistent with that behavior.

00:46 Okay.

00:47 So right off the bat, a linear molecule where the outer one pulls electrons more, co2.

00:54 Like if we draw the lewis structure, we know that it's a linear molecule with two double bonds for each oxygen, and oxygen is more electronegative than carbon, so it's going to pull electrons.

01:05 And so you'll have a net positive charge in the middle, net negative charge on the ends.

01:08 That's consistent with that.

01:10 Is there anything else that's linear like that? so, so3 is going to have three regions of electron density, so we can rule that out.

01:20 That's not applicable.

01:22 Sf2, let's consider that.

01:24 So sulfur has six electrons, and let me erase this.

01:32 So for sf2.

01:35 So for six electrons, there's two fluorines, which each have seven, 14.

01:38 So this is 20 electrons, and then each one wants three.

01:46 Each of the three wants eight...