4.25 part a

[Alex Kashou]

Ok so i understand that the dipoles in CH2Cl2 will point towards the Cl's because they are more electronegative and I see through structure how it can be polar. But doesn't it depend on where the Cl and H are placed in order to determine if it is polar. Because if the Cl are directly across from each other in this shape, it would be nonpolar, right?

[Vasiliki G Dis1C]

The C-Cl bond is polar, and the C-H is almost nonpolar(it has small polarity, the importance is that it is different in polarity from C-Cl). Even if the arrangement is symmetrical, the different polarities of the C-H bond and the C-Cl bond will have an effect on the entire molecule and make the molecule polar.

[Charles Ang 1E]

Alex is correct. Even if the molecule is symmetrical, it is still possible to be polar. The bond polarities, which can be determined by electronegativity, must be checked in order to determine this. A good example is HCN where despite being linear, is polar.