Question

Question #e047b

Answer 1

You write soluble ionic compounds as cation and anion.

In your case, barium nitrate, `Ba(NO_3)_2`, is composed of barium cations, `Ba^(2+)`, and nitrate anions, `NO_3""^(-)`, which means that, in aqueous solution, you would write it like this

`Ba_((aq))^(2+) + 2NO_(3(aq))""^(-)`

The 2 stoichiometric coefficient comes from the fact that you need two nitrate anions to balance the charge of the barium cation.

![http://www.guidechem.com/cas-100/10022-31-8.html]()

So, always try to identify the cation and anion first, and figure out the stoichiometric coefficients by looking at the charges.

Keep in mind that ionic compounds follow the cross-over rule. Here's an example of how that works with calcium nitrate, which is very similar to barium nitrate in terms of cation and anion charges

![https://courses.candelalearning.com/cheminter/chapter/chemical-nomenclature/]()