## Lewis Structure

Rachel-Weisz3C
Posts: 66
Joined: Fri Sep 28, 2018 12:23 am

### Lewis Structure

In discussion, we had to draw the Lewis Structure of ClCN. Which looks like: Cl-C$\equiv$N (with 2 lone pairs on Cl and one lone pair on N). I was wondering if there was anyway this compound could be represented with a triple bond on the Cl instead of the N, like: Cl$\equiv$C-N . And if this is not possible, why not?

Nicolette_Canlian_2L
Posts: 77
Joined: Fri Sep 28, 2018 12:25 am
Been upvoted: 1 time

### Re: Lewis Structure

I am confused on this lewis structure in general. Is the octet rule for chlorine not supposed to be fulfilled?

MaanasO 1A
Posts: 72
Joined: Fri Sep 28, 2018 12:26 am

### Re: Lewis Structure

Hi Rachel!

Yes, the compound in question could theoretically have a triple bond between C and Cl and a single bond between C and N. The Cl atom would have 1 lone pair (giving it a formal charge of 7-(2+3) = +2) and the N atom would have 3 lone pairs (giving it a formal charge of 5 - (6+1) = -2). The formal charges would sum to 0 and the total electron count would be accurate. However, this is a very unstable structure looking at the formal charges, so you wouldn't represent ClCN in this fashion.

Hope that helps!

Gary Qiao 1D
Posts: 66
Joined: Fri Sep 28, 2018 12:26 am

### Re: Lewis Structure

Hey Nicolette,
I think there actually are 3 lone pairs on the Cl instead of 2, or else the total valence electrons would not match up