Complete and balance the precipitation reactions. Include physical states in your equations.

Ba(NO3)2(aq) + CuSO4 (aq)--->

K3PO4(aq)+MgCl2 (aq)---->

Ba(NO3)2(aq) + CuSO4(aq) ---> BaSO4(s) + Cu(NO3)2(aq)

K3PO4(aq) + MgCl2(aq) ---> KCl(aq) + Mg3(PO4)2(s)

Why did the chemistry professor break up with their partner? Because there was no "chemistry" between them!

Ba(NO3)2(aq) + CuSO4(aq) ---> BaSO4(s) + Cu(NO3)2(aq)

K3PO4(aq) + MgCl2(aq) ---> KCl(aq) + Mg3(PO4)2(s)

To balance precipitation reactions, we need to determine the products that form and ensure that the number of atoms of each element on both sides of the equation is equal. Precipitation reactions occur when an insoluble solid, known as a precipitate, forms during the mixing of two aqueous solutions.

1) Ba(NO3)2(aq) + CuSO4(aq) ----> BaSO4(s) + Cu(NO3)2(aq)
(Barium Nitrate + Copper(II) Sulfate ----> Barium Sulfate + Copper Nitrate)

Balancing the equation:
Ba(NO3)2(aq) + CuSO4(aq) ----> BaSO4(s) + Cu(NO3)2(aq)

2) K3PO4(aq) + MgCl2(aq) ----> KCl(aq) + Mg3(PO4)2(s)
(Potassium Phosphate + Magnesium Chloride ----> Potassium Chloride + Magnesium Phosphate)

Balancing the equation:
2K3PO4(aq) + 3MgCl2(aq) ----> 6KCl(aq) + Mg3(PO4)2(s)

Note: It is important to check solubility rules to determine if the products are soluble or not. In the case of BaSO4 and Mg3(PO4)2, they are insoluble, hence precipitates, while Cu(NO3)2 and KCl are soluble and remain in the aqueous state.

Didn't I do this for you a couple days ago? You need to know the solubility rules. Here is a simplified set.

http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html

The first one is done this way.
Ba(NO3)2(aq) + CuSO4((aq) ==> BaSO4(s) + Cu(NO3)2(aq)