Question

What occurs when `Ba(NO_3)_2(aq)` and `Na_2SO_4(aq)` are mixed?

Answer 1

Well, all nitrates are soluble.........

Explanation:

And all sodium salts are soluble...and most sulfates are soluble. Barium sulfate, however, is reasonably insoluble

And should barium nitrate, and sodium sulfate be mixed in aqueous solution, a `"metathesis"` or `"partner exchange reaction"` should occur, and insoluble barium sulfate should precipitate. How do I know this? How else but by experiment? And 20 or so years ago I did the same experiment as you did.

`Ba(NO_3)_2(aq)+Na_2SO_4(aq) rarr BaSO_4(s)darr + 2NaNO_3(aq)`

And we could write the net ionic equation, given that nitrate and sodium salts are all soluble......

`Ba^(2+) + SO_4^(2-) rarr BaSO_4(s)darr`

None of this is a replacement for doing the experiment, and noting down your observations.