## Dipole Moment Arrows

Lauren Ton 4B
Posts: 9
Joined: Fri Sep 26, 2014 2:02 pm

### Dipole Moment Arrows

When you draw a dipole moment, the "old" way of signifying the dipole moment was an arrow pointing towards the negative charge. The more modern way to note a dipole moment is an arrow pointing towards the positive charge. Why did this change? And what do the arrows signify (if they signify anything besides a dipole moment)?

Thank you.

FrancoNancy_Sec1L
Posts: 26
Joined: Fri Sep 20, 2013 3:00 am

### Re: Dipole Moment Arrows

No, the dipole (arrow ) still points toward the negative charge.

Jennifer Aguayo 1I
Posts: 26
Joined: Fri Sep 26, 2014 2:02 pm

### Re: Dipole Moment Arrows

Hi,
I agree, I think that the direction of the arrow does change. In the textbook on page 77 it says that:
The original, "old," is when the arrow points towards the negative charge.
In the modern convention, the arrow points towards the positive charge.
Lauren, I am not sure why this changed. Sorry

But my guess is that for the exam/for this class we will be using the original convention since that is what Dr. Lavelle went over during lecture. But I am not completely sure, please someone correct me if I am wrong.

Justin Le 2I
Posts: 142
Joined: Fri Sep 26, 2014 2:02 pm

### Re: Dipole Moment Arrows

For me personally, the old method for drawing dipole moment arrows is much clearer and understandable because there is a plus sign that is pointing towards the delta negative. If you still have questions, you can ask your TA.

MattDavid1d
Posts: 8
Joined: Thu Oct 01, 2015 3:00 am

### Re: Dipole Moment Arrows

As far as I am aware, both ways are essentially the same with merely a reversal in sign. How it begins/last which way the arrow points is arbitrary as long as you remain consistent with that direction throughout the entirety of the problem.

Chem_Mod
Posts: 18400
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 435 times

### Re: Dipole Moment Arrows

Dipole arrows should be drawn from positive to negative. That way, the direction the arrow points represents where an electron is more likely to be found.