Na2PO4+CaCl2 yields?

At least try...

When you dissolve these substances in water, you'll get this:

Na_2PO_4 \rightleftharpoons 2Na^+ + PO_4^{-2}

CaCl_2 \rightleftharpoons Ca^{+2} + 2Cl^-

Basically, both of the substances (salts) ionize. You have sodium, phosphate, calcium, and chloride ions in solution. They will mix up.

Mix each cation (positive ion) with each anion (negative ion). That's what you'll get from the "reaction".

Ca^{+2} + PO_4^{-2} \rightleftharpoons CaPO_4

Na^+ + Cl^- \rightleftharpoons NaCl