00:01
Similar to problem 123, problem 125 asks which of the molecules in problem 121 have a net dipole moment, or in other words, which of these molecules was polar.
00:14
So part a here is xenon dichloride.
00:19
So i've drawn here for you the structure that we determined for each of these molecules in problem 121.
00:27
And here you can see that xenon is bound to two chlorine atoms and has three surrounding lone pairs of electrons.
00:38
So in general, lone pairs of electrons and bonds don't cancel each other out charge -wise, meaning that they're not symmetrical, if you consider them together.
00:51
But if you consider lone pairs against lone pairs and bonds against bonds, you can see that this xenon has evenly spaced electron pairs that cancel each other out as well as evenly spaced or symmetrical xenon chlorine bonds.
01:12
So what that means is that this molecule is actually symmetrical and does not have a permanent or net dipole moment.
01:24
On the other hand, this iodine trichloride in part b here is imbalanced in that it has these three iodine -chlorine bonds balanced against two lone pairs of electrons...