[lokemer]

This is an excerpt from my book:

Formula Equation:
K2CrO4(aq) + Ba(NO3)2(aq) --> BaCrO4(s) + 2KNO3(aq)

My only question is how do you predict the state of matter when it changes.  I may have just forgotten this part of lecture.

What I mean by that is why in KNO3 a Solid but Potassium and Nitrate are both aqueos before and now a I supposed to predict this change?

[Arkcon]

Barium chromate is insoluble in water.  You'll know that using solubility rules, although chromate is a little obscure to expect you to know.  Consider this however: if both products are soluble, do you get a reaction?