A solution of 5.00 g oxalic acid (H2C2O4, M = 90.04) in 100.0 g H2O has a freezing point of –1.31 °C — Solutions Chemistry Question

A solution of 5.00 g oxalic acid (H₂C₂O₄, M = 90.04) in 100.0 g H₂O has a freezing point of –1.31 °C. What is the percent ionization of oxalic acid in this solution? The freezing point depression constant of water is Kf = 1.86 °C m^-1.