Question

Which compounds produce three ions per formula unit by dissociation when dissolved in water? (Select all that apply)a) K2SO4b) Al(NO3)3c) Li3PO4d) Ca(NO3)2

Answer 1

These four are soluble compounds and we will determine which of them produce three ions by looking at their dissociation equations.

a) K₂SO₄ ----> 2 K⁺ + SO₄²⁻ (produces 3 ions)

b) Al(NO₃)₃ ---> Al³⁺ + 3 NO₃⁻ (produces 4 ions)

c) Li₃PO₄ ----> 3 Li⁺ + PO₄³⁻ (produces 4 ions)

d) Ca(NO₃)₂ ----> Ca²⁺ + 2 NO₃⁻ (produces 3 ions)

Answer: a) K₂SO₄ and d) Ca(NO₃)₂