## Polar

Matia Kim 1B
Posts: 60
Joined: Fri Apr 06, 2018 11:03 am

### Polar

How do you know which resonance structure to use if they are polar? Is it always by lowest charge?

Michael_Navarro_1H
Posts: 29
Joined: Fri Sep 28, 2018 12:17 am

### Re: Polar

Usually, you want to keep the negative charges on the most electronegative atoms and keep the other atoms at a FC of 0.

Daniel Lai
Posts: 65
Joined: Fri Sep 28, 2018 12:28 am

### Re: Polar

If the formal charges are close to 0, then you use that one.

Daniel Lai
Posts: 65
Joined: Fri Sep 28, 2018 12:28 am

### Re: Polar

Polarity does not affect it, only having the formal charges closest to 0 matters.

204765696
Posts: 23
Joined: Wed May 16, 2018 3:00 am

### Re: Polar

You use the one with formal charges closest to 0.

melodyzaki2E
Posts: 61
Joined: Fri Sep 28, 2018 12:18 am

### Re: Polar

polarity shouldn't affect the resonance structure, focus on the formal charge when determining resonance.

kimberlyrose1G
Posts: 44
Joined: Fri Sep 28, 2018 12:27 am

### Re: Polar

You calculate the formal charge of each possibility and focus on the one that has an f.c. closest to zero

MichaelMoreno2G
Posts: 60
Joined: Fri Sep 28, 2018 12:26 am

### Re: Polar

Can someone explain how we identify if a bond is polar or non-polar?

LuisG14A1J
Posts: 9
Joined: Fri Sep 28, 2018 12:17 am

### Re: Polar

MMoreno3K wrote:Can someone explain how we identify if a bond is polar or non-polar?

To identify if a bond is polar or non polar depends on the structure of the molecule. If the Dipoles all cancel each other out when all the directions are considered for the structure then the molecule is non-polar. Polarity usually occurs as a result of Electron Lone Pairs offsetting all the molecules from each other.
Bonds can be polar if the Formal Charge (FC) of the two elements being considered are different in their FC.
But for most structures that express non-polar characteristics like HF: It's linear structure, FC cancels out on both H and F to be 0. The way to determine if that molecule is polar or non polar is by the unequal sharing of electrons. Fluorine unequally shares the electrons with Hydrogen, resulting in a slight negative charge on the shape of it. (If you look up how an HF molecule looks it looks tear drop shaped because of the large electron shell of the Fluorine atom holding the electrons) F holds all the electrons and creates a small net negative charge in that direction, and H has so few electrons near it that it creates a small net positive charge in its direction. It's because of the high electro-negativity of the Fluorine atom.