## dipole moments

emmaferry2D
Posts: 129
Joined: Wed Sep 30, 2020 9:47 pm

### dipole moments

When drawing the arrow for net delta and delta positive in a molecule with a dipole moment which way does the arrow point? I believe in the textbook it said the arrow head should be pointed towards the delta positive atom, but I think in lectures lavelle was doing the opposite.

Savana Maxfield 3F
Posts: 161
Joined: Wed Sep 30, 2020 10:00 pm

### Re: dipole moments

I've understood it as the arrow points to the more electronegative element. But if someone else has a better explanation I would be interested to hear!

SashaAnand2J
Posts: 90
Joined: Wed Sep 30, 2020 9:37 pm

### Re: dipole moments

Follow Dr. Lavelle! The arrow should be pointing towards the negative dipole, because it indicates where electrons are being pulled.

Ayesha Aslam-Mir 3C
Posts: 115
Joined: Wed Sep 30, 2020 9:43 pm

### Re: dipole moments

Would you only draw these for a dipole moment though? I guess I want to know when you would even draw the arrows; would it be in an ionic compound specifically, or the temporary dipole moment in covalent compounds? Also, I wanted to clarify you wouldn't have a dipole moment in a compound made of the same element.

Lillian
Posts: 69
Joined: Wed Sep 30, 2020 9:48 pm

### Re: dipole moments

SashaAnand3G wrote:Follow Dr. Lavelle! The arrow should be pointing towards the negative dipole, because it indicates where electrons are being pulled.

What determines the negative dipole again?

Brian_Wu_3B
Posts: 93
Joined: Wed Sep 30, 2020 9:41 pm

### Re: dipole moments

A negative dipole is the more electronegative element because they pull harder on the electrons compared to the other atom.

Posts: 164
Joined: Wed Sep 30, 2020 9:46 pm
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### Re: dipole moments

I went to Johnathan's step-up and he gave us a little trick: the side of the arrow with the dashed line looks like a plus sign so you draw the plus sign end on the positive particle charge and draw the arrowhead toward the negative partial charge. Also, I just remember electrons are moving toward the more electronegative atom so the arrow points toward that atom.

AnnaNovoselov1G
Posts: 78
Joined: Wed Sep 30, 2020 9:51 pm
Been upvoted: 1 time

### Re: dipole moments

Lillian wrote:
SashaAnand3G wrote:Follow Dr. Lavelle! The arrow should be pointing towards the negative dipole, because it indicates where electrons are being pulled.

What determines the negative dipole again?

The more electronegative atom has the negative dipole because it pulls electrons toward itself more! Electronegativity increases across a period because zeff (effective nuclear charge) increases and electronegativity decreases down a period because the shielding increases. Hope this helps!

Keeryth Sandhu 1H
Posts: 97
Joined: Wed Sep 30, 2020 10:04 pm

### Re: dipole moments

I've understood to draw the arrow towards the atom with negative partial charge (the more electronegative element)

Lillian
Posts: 69
Joined: Wed Sep 30, 2020 9:48 pm

### Re: dipole moments

AnnaNovoselov1G wrote:
Lillian wrote:
SashaAnand3G wrote:Follow Dr. Lavelle! The arrow should be pointing towards the negative dipole, because it indicates where electrons are being pulled.

What determines the negative dipole again?

The more electronegative atom has the negative dipole because it pulls electrons toward itself more! Electronegativity increases across a period because zeff (effective nuclear charge) increases and electronegativity decreases down a period because the shielding increases. Hope this helps!

Ah so if a molecule consists of one central atom and multiple equally electronegative atoms, they would cancel each other out?

Isabella Cortes 2H
Posts: 90
Joined: Wed Sep 30, 2020 9:37 pm

### Re: dipole moments

I would follow what Dr. Lavelle said and have the arrows point toward the more electronegative atoms. I hope this helps!!