K3PO4 is an ionic compound that dissociates itself upon its addition to the solvent to form a solution. When it is in the solution it forms ions. The balanced dissociation for for K3PO4 is
K3PO4 ---> 3K^+ + PO4^-3
The dissociation of 1 mole of K3PO4 forms 3 moles of potassium ions (K^+) and 1 mole of phosphate ions (PO4^-3). The equation is already balanced.