Final answer:
The precipitate formed when barium nitrate is mixed with sodium sulfate is barium sulfate (BaSO4), which is a white, poorly soluble solid.
Step-by-step explanation:
When barium nitrate and sodium sulfate solutions are mixed, a precipitate is formed due to a double displacement reaction. The ions in the solution switch partners, resulting in the formation of new compounds. One of these new compounds formed is barium sulfate (BaSO4), which is poorly soluble in water and will precipitate out of the solution. The reaction can be represented by the following chemical equation:
Ba(NO3)2(aq) + Na2SO4(aq) → BaSO4(s) + 2 NaNO3(aq)
Here, BaSO4 is the precipitate, and it is a white solid that will be observed settling out of the mixture.