J.R. S. answered 09/19/22
Ph.D. University Professor with 10+ years Tutoring Experience
3CsCl(aq) + K3PO4(aq) ==> Cs3PO4(aq) + 3KCl(aq) NR
There is some controversy over the solubility of Cs3PO4, but since Cs is a group 1 metal, it is more than likely a soluble salt, and so is indicated as (aq).