What is the Lewis structure of HCN?

1 Answer
anor277
Oct 29, 2015

Cyanide anion, #5# #+# #4# valence electrons: #[:C-=N:]^-#. There is a formal negative charge associated with this anion. Where does it reside?

Explanation:

The nitrogen nucleus has 3 electrons from the triple bond, and 2 electrons from its lone pair, and 2 inner core electrons; the associated charge balances the 7 protons in the nitrogen nucleus, so the nitrogen is formally neutral.

The carbon atom has (or shares) 3 electrons from the triple bond, and a lone pair of electrons, which it owns. With 2 inner core electrons, this makes 7 electrons with which it is associated. Since, the atomic number of carbon is #6#, the carbon atom is formally negatively charged.

When I write #H-C-=N:#, the carbon atom has a share of 4 electrons, and with 2 inner core electrons it is formally neutral, as is the nitrogen and the hydrogen.

Related questions
See all questions in Lewis Dot Diagram
Impact of this question
22741 views around the world
You can reuse this answer
Creative Commons License