Final answer:
Upon mixing (NH₄)₃PO₄ and Na₂SO₄ in an aqueous solution, no net ionic equation can be formulated because soluble products are formed. In this reaction, all ions remain in solution, and there is no precipitation of solid products.
Therefore, the correct answer is option A) (NH₄)₃PO₄(aq) + Na₂SO₄(aq) → (NH₄)₂SO₄(s) + Na₃PO₄(aq).
Step-by-step explanation:
When (NH₄)₃PO₄ (ammonium phosphate) and Na₂SO₄ (sodium sulfate) are combined in an aqueous solution, potential products include ammonium sulfate (NH₄₂SO₄) and sodium phosphate (Na₃PO₄). However, both reactants and their potential products are soluble in water.
Consequently, there is no formation of a solid precipitate. In the absence of a solid product, no net ionic equation can be established for this reaction, as all ions continue to exist in solution.
This scenario is analogous to the reference equation Na₂SO₄ (aq) + 2NH₄I (aq) → 2 NaI (aq) + (NH₄)₂SO₄ (aq), where both resulting compounds are aqueous and no net ionic equation is derived.
Therefore, the correct answer is option A) (NH₄)₃PO₄(aq) + Na₂SO₄(aq) → (NH₄)₂SO₄(s) + Na₃PO₄(aq).