5. 250.0 ml of 0.08 CuSO4 solution was passed through a column filled with 10 g cation exchanger. 50.00 ml portions of the solution leaving the column were titrated with a 0.1 N solution of sodium thiosulfate and the following volumes of thiosulfate were obtained, which went for titration in ml: 1-0; 2-12.00; 3-25.00; 4-39.20; 5-39.20. Calculate the dynamic exchange capacity of the cation exchange resin for copper.