Explain how could you use a precipitation reaction

Question

Explain how could you use a precipitation reaction to separate each of the following pairs of cations? Write down the formula for each reactant you would add, and write down a balanced net ionic equation for each reaction.

1.Cl^- and NO₃^-

2.Fe⁺² and Ba⁺²

3.SO₄^-2 andCO₃^-2

4.Pb ⁺² and Ni⁺²