# Write the net ionic equation that describes the reaction that occurs when a solution of barium nitrate is added to a flask containing sulfate ions?

Jul 24, 2017

${\text{Ba"_ ((aq))^(2+) + "SO"_ (4(aq))^(2-) -> "BaSO}}_{4 \left(s\right)} \downarrow$

#### Explanation:

The idea here is that barium nitrate is a soluble ionic compound, which implies that it dissociates completely in aqueous solution to produce barium cations, ${\text{Ba}}^{2 +}$, and nitrate anions, ${\text{NO}}_{3}^{-}$.

So when barium nitrate is dissolved in water, it exists as dissociated ions

${\text{Ba"("NO"_ 3)_ (2(aq)) -> "Ba"_ ((aq))^(2+) + 2"NO}}_{3 \left(a q\right)}^{-}$

When you mix this solution with a solution that contains sulfate anions, ${\text{SO}}_{4}^{2 -}$, an insoluble solid that precipitates out of the solution will be produced. This insoluble solid is called barium sulfate, ${\text{BaSO}}_{4}$.

So you can say that when these two solutions are mixed, you have

${\text{Ba"_ ((aq))^(2+) + 2"NO"_ (3(aq))^(-) + "SO"_ (4(aq))^(2-) -> "BaSO"_ (4(s)) darr + 2"NO}}_{3 \left(a q\right)}^{-}$

Since the nitrate anions are present on both sides of the chemical equation, you can say that they are spectator ions.

This implies that you can eliminate them

"Ba"_ ((aq))^(2+) + color(red)(cancel(color(black)(2"NO"_ (3(aq))^(-)))) + "SO"_ (4(aq))^(2-) -> "BaSO"_ (4(s)) darr + color(red)(cancel(color(black)(2"NO"_ (3(aq))^(-))))

to get the net ionic equation, which looks like this

${\text{Ba"_ ((aq))^(2+) + "SO"_ (4(aq))^(2-) -> "BaSO}}_{4 \left(s\right)} \downarrow$

Barium sulfate is a white solid that will precipitate out of the solution. 