# Question 36d03

Oct 5, 2015

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

#### Explanation:

You're dealing with two soluble compounds, magnesium sulfate, ${\text{MgSO}}_{4}$, and barium nitrate, "Ba"("NO"_3)_2, tha are completely dissociated in aqueous solution.

${\text{MgSO"_text(4(aq]) -> "Mg"_text((aq])^(2+) + "SO}}_{\textrm{4 \left(a q\right]}}^{2 -}$

${\text{Ba"("NO"_3)_text(2(aq]) -> "Ba"_text((aq])^(2+) + 2"NO}}_{\textrm{3 \left(a q\right]}}^{-}$

This means that when you're mixing two solutions containing these compounds, you are essentially mixing cations and anions.

The barium cations and the sulfate anions will react to form barium sulfate, ${\text{BaSO}}_{4}$, an insoluble solid. The other ions are spectator ions, meaning that they continue to exist as ions after the two solutions are mixed.

So, the complete equation for thsi double replacement reaction looks like this

"MgSO"_text(4(aq]) + "Ba"("NO"_3)_text(2(aq]) -> "BaSO"_text(4(s]) darr + "Mg"("NO"_3)_text(2(aq])#

The complete ionic equation is

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

The net ionic equation, which only shows the ions that react to form the solid, will looks like this

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