What will create a insoluble salt with a potassium ion

Explanation:

1) The dissolution of the salt potassium sulfite:

K₂SO₃(aq) → 2K⁺(aq) + SO₃²⁻(aq).

Potassium has +1 charge because it lost one electron to accomplish stabile electron configuration of noble gas argon.

2) From dissolution reaction: n(K⁺) : n(SO₃²⁻) = 2 : 1.

n(K⁺) = 0.700 mol.

0.700 mol : n(SO₃²⁻) = 2 : 1.

n(SO₃²⁻) = 0.700 mol ÷ 2.

n(SO₃²⁻) = 0.350 mol; amount of sulfite anions.