* Potassium Sulfate: K₂SO₄

* Potassium (K) has a +1 charge.

* Sulfate (SO₄) has a -2 charge.

* To balance the charges, you need two potassium ions (K⁺) for every sulfate ion (SO₄²⁻).

* Oxalic Acid: H₂C₂O₄

* Hydrogen (H) has a +1 charge.

* Oxalate (C₂O₄) has a -2 charge.

* Two hydrogen ions (H⁺) are needed to balance the charge of one oxalate ion (C₂O₄²⁻).