Question #0bdcb

1 Answer
Mar 13, 2015

It will occur since one product (#BaSO_4#) is insoluble.

According to "Solubility Rules", the first family, the Alkali metals (Li, Na, K, Rb, Cs, F) are always soluble in water.
NO3 -1, C2H3O2 -1, and NH4+1 are also always soluble in water.
And, the Halogens, are always soluble as long as you do not have Silver (Ag), Lead (Pb) or Mercury (Hg) ions that came from a compound of those metals in the same container as the halogen compounds. (for example, AgNO3 + NaCl will produce an AgCl precipitate.
Hydrogen (H) is also always soulble as long as it is in the first part of the formula and not as OH.
So, you can see from your reaction, that the NO3 from the Ba(NO3)2 is soluble, and the Na from your Na2SO4 is soluble, leaving the compound BaSO4 to precipitate since Ba and SO4 are not part of the "Solubility Rules".