[High School - Chemistry] Polar vs Non polar Molecules (giving 10k creidts)

Re: [High School - Chemistry] Polar vs Non polar Molecules (giving 10k creidts)

Chem major here

A thing to note about polarity:
The thing with polarity is that your permanent dipole moment (which contributes to whether a molecule is polar or not) is continuous and depends on the molecule. There isn't really a hard rule as to when something is polar or non-polar. Some books will give you a certain cutoff for the dipole moment, claiming that anything with a permanent dipole greater than that value is polar, while anything less than that value is non-polar. As far as I know though, there isn't really a widely accepted, discrete cutoff point for whether a molecule can be called polar or non-polar.
Think of different molecules having different shades of gray, and polar/non-polar as being the categories of either white or black. More often than not, polar/non-polar are used as descriptive relative terms.

Anyway, to answer your question:
Most of what you put down looks right to me.
SF4, though, has a distorted tetrahedron (seesaw) molecular geometry so it's asymmetrical because of its lone pair. As a result, I'd like to think it's polar.
IBr5 has a square pyramidal molecular geometry so I think it's polar as well.

Hope that helps!

Re: [High School - Chemistry] Polar vs Non polar Molecules (giving 10k creidts)

SF4 and IBr5 are polar, since the central atom has an excess of electrons and makes an electron pair.

The rest seems good.

Re: [High School - Chemistry] Polar vs Non polar Molecules (giving 10k creidts)

I'm in AP Chem. :P
Polar - NH3, CH3OH, N2H4, H2O, SO2, HCN, CH2O, ClF3, IBr5
Non polar - CO2, PCl5
SF4 is non-polar w/ polar bonds. (Thinking polar)

Seems you are right on for most of it.

Re: [High School - Chemistry] Polar vs Non polar Molecules (giving 10k creidts)

This, because SF4 is a sawhorse and IBr5 is a square pyramid.
Also, a fail Lewis dot structure of those 2:


In regards to PCl5, it has polar bonds but they cancel out in all directions since it's a trigonal bipyramid.

Re: [High School - Chemistry] Polar vs Non polar Molecules (giving 10k creidts)

Thanks everyone. And yea I was really doubting about IBr5 and SF4 because of their lone pairs and I just realized SF4 is asymmetrical, and seesaw or sawhorse as WSCB mentioned so it must be polar.

giving 10k to evnoir, wscb, ninja and emerald

Re: [High School - Chemistry] Polar vs Non polar Molecules (giving 10k creidts)

Teehee ninja'd. It's ok though! As long as you got your questions answered

Re: [High School - Chemistry] Polar vs Non polar Molecules (giving 10k creidts)

So many Chemistry nerds on FFR xD

Also, the title says "giving 10k creidts"
I will expect some creidts.

I don't need the credits btw

Re: [High School - Chemistry] Polar vs Non polar Molecules (giving 10k creidts)

The only real Chem nerds are the Chem majors.

Taking AP Chem/A-level Chem in high school or General (even organic) Chemistry in college doesn't qualify you to be a Chem nerd

So, any fellow chem majors?

Re: [High School - Chemistry] Polar vs Non polar Molecules (giving 10k creidts)

hehe, just read your edited post so no worries, ill give you 10k as well cause creds don't mean anything to me. lol

Re: [High School - Chemistry] Polar vs Non polar Molecules (giving 10k creidts)

i no that this is chemistry and all that mumbo jumbo but i always wondered why people were diagnosed with a bipolar psychological disorder..... never understood that word choice

Re: [High School - Chemistry] Polar vs Non polar Molecules (giving 10k creidts)

Polar means opposite, so bi-polar meaning 2 opposite ends of the emotional spectrum.