Question

Write a balanced complete ionic equation for the precipitation of Mg(OH)2from an aqueous solution of NaOH and MgSO4. Also condense this to a net ionic equation.

Answer 1

The balanced complete ionic equation is:

Mg²⁺(aq) + SO₄²⁻(aq) + 2Na⁺(aq) + 2OH⁻(aq) → Mg(OH)₂(s) + 2Na⁺(aq) + SO₄²⁻(aq)

The net ionic equation is:

Mg²⁺(aq) + 2OH⁻(aq) → Mg(OH)₂(s)

Step-by-step explanation

When aqueous NaOH and MgSO4 are combined, solid Mg(OH)2 and aqueous Na2SO4.

The balanced complete molecular equation for the precipitation reaction is:

MgSO₄(aq) + 2NaOH(aq) → Mg(OH)₂(s) + Na₂SO₄(aq)

The balanced complete ionic equation for the precipitation reaction is:

Mg²⁺(aq) + SO₄²⁻(aq) + 2Na⁺(aq) + 2OH⁻(aq) → Mg(OH)₂(s) + 2Na⁺(aq) + SO₄²⁻(aq)

The spectator ions are SO₄²⁻(aq) and Na⁺(aq). Therefore, condensing the complete ionic equation will result in a net ionic equation given below:

Mg²⁺(aq) + 2OH⁻(aq) → Mg(OH)₂(s)