Suppose a 1.38 g sample of Unknown X containing K₂C₂O₄ was dissolved in 25 mL of DI water and 25mL 3MH₂SO₄ and then titrated with 0.0655M KMnO₄. The sample required 28.82 mL of titrant to reach the endpoint. Determine the mass percent K₂C₂O₄ in sample Unknown X.