Thread: How is Hydrogen Cyanide bonded?

Is it bonded ionically or covalently?

Its name 'Hydrogen Cyanide' follows the naming conventions of an ionic compound.
Cyanide is a polyatomic ion of CN-. This would allow it form an ionic bond with a hydrogen cation.

However, they are both non-metals, thus cannot be bonded ionically. If it is bonded covalently, why is it named in such a way?

Thankyou

There is some ionic character, when dissolved in water HCN will partially dissociate into H⁺ and CN^-. In the gas phase it is a molecule with the C atom in the middle with a single bond to the H and a triple bond to the N.

Is HCl covalently bound or ionically?

It depends on if it forms ions when dissolved in water. (or when melted/vaporised)

And HCl splits into 2 parts when in water.

HCN basically does the same.

Not sure what the exact rule is for this to be called ionic, but i think this covers most of the issues.

Thank you for the quick responses. They answered my question without any issues.

Originally Posted by Zwolver

Is HCl covalently bound or ionically?

It depends on if it forms ions when dissolved in water. (or when melted/vaporised)

And HCl splits into 2 parts when in water.

HCN basically does the same.

No. There is a big difference in the pK_a for HCl and HCN. HCN has a pK_a of 9.21 (compared to –7.0 for HCl) so it is essentially covalent in aqueous solution.

This is why I said "some ionic character" and "partially disscociate" but I couldn't be bothered to look up the numbers