when aqueous solutions of copper II nitrate and sodium phosphate are mixed, sodium nitrate and copper II phosphate are formed. In the balanced chemical equation what is the coefficient of sodium nitrate?

Answer 1

And what is your trouble with this?

Answer 2

The balanced equation is
3 Cu(NO3)2 + 2 Na3(PO4) -> 6 NaNO3 + Cu3(PO4)2

Find the coefficient of sodium nitrate.