Question

What happens when you mix Potassium Iodide and Barium Nitrate together?

Does it form a precipitate? if so, I need details.

Answer 1

No precipitate

Explanation:

This is an example of a double displacement reaction, where the anions and cations switch partners. Sometimes, this forms a precipitate if one product is insoluble in the solvent, which we usually assume is water `(H_2O)`.

So, the chemical reaction will be:

`KI(aq)+Ba(NO_3)_2(aq)->KNO_3(aq)+BaI_2(aq)`

Balancing the equation, it becomes:

`2KI(aq)+Ba(NO_3)_2(aq)->2KNO_3(aq)+BaI_2(aq)`

According to the solubility rules, almost all nitrates can be assumed to be soluble, so potassium nitrate `(KNO_3)` is definitely going to be aqueous. Barium iodide `(I_2)` is also completely soluble but only if it comes as a hydrate `(BaI_2(H_2O)_2)`. Since this reaction takes place in two aqueous solutions, there are definitely some water molecules that are freely available and readily become ligands to the barium iodide molecule.