Why is Ca(NO_3)_2 a ionic bond? I thought all of them are nonmetals so it should be a covalent bond?

1 Answer
Nov 14, 2017

The nitrate ion, NO_3^(-) is a discrete species.....

And calcium is a METAL......

Explanation:

You look at the Lewis formulation of nitrate, THREE of the four atoms bear formal charges....

O=stackrel(+)N(-O^(-))_2-=NO_3^(-)

We say that the nitrogen is quaternized and has donated its lone pair to an oxygen atom.....the charge is balanced by the tow oxygen atoms that bear a formal negative charge....

Calcium is in Group 2 of the Periodic Table, so it typically forms Ca^(2+) upon oxidation.....

Ca(s) +DeltararrCa^(2+) + 2e^(-)

The salt balances charge....and so Ca^(2+) + 2xxNO_3^(-) gives...

Ca(NO_3)_2...........as the salt of a metal and an acid.