Determining polarity

[nartnad]

---

Members don't see this ad.

Theres a destroyer question that asks if these molecules are polar or non-polar:

CS2, AlCl3, BCl3, SO2, SBr2

I can see why theyre polar after drawing out the lewis structures, but what is the most time efficient way to approach this problem?

 

[loveoforganic]

You just have to be able to recognize it quickly through practice I guess. Carbon makes 4 bonds, so CS2 is going to be planar. Al makes 3 bonds and has no lone pair so it's trigonal planar. Same for BCl3. SO2 and SBr2 are both polar, so if there's only supposed to be one answer idk. SO2 is a crappy molecule to throw into that mix.