Question

You have 2 chemicals A (solid) and B (solid), but you do not know the exact composition of either one of them. You do know that all together, there is SOME combination of sodium, barium, chloride and phosphate (PO4^3-) present. You dissolve both chemicals in water. Then you mix A and B together. You observe there is a cloudy precipitate that forms in a clear colorless solution (mostly water?)

Predict and write 2 possible balances equations for the 2 most likely reactions that could've ocurred.

PLEASE HELP. I don't know how to start, or what to do. i just need to figure out what goes where and how i know where to put things. I can balance the equation myself, i just need help on how to figure out what to do. Thanks

Answer 1

I can offer some help but it won't answer the question completely. With Na^+, Ba^+2, Cl^-, and PO4^-3, you could have these possibilities.
Na3PO4 and BaCl2 or NaCl and Ba3(PO4)2. Since both are soluble in water, I think the possibility is much higher of having the Na3PO4 and BaCl2. If aqueous solutions of those are mixed one would have
Ba3(PO4)2 (a white ppt) + NaCl.
However, I can't find Ba3(PO4)2 listed in the Merck Index of chemicals nor can I find it in the The Handbook of Physics and Chemistry. And that is the only possibility I see. If you have been studying phosphate chemistry, you probably know that phosphate ion does a lot of things and one can get metaphosphates, pyrophosphates, orthophosphates, etc. Perhaps the answer lies there.