Le chateliers principle and sulfuric acid

Question

Assignment:

For the following reaction HSO₄^-(aq) + H₂O <-> H₃O+(aq) + SO₄^2-

A.) How will the equilibrium change when Na₂SO₄ is added?

B.) How will the equilibrium change when NaHSO₄ is added?

C.) Is this reaction endothermic or exothermic?

Provide complete and step by step solution for the question and show calculations and use formulas.