Solving a chemistry problem

48. What mass of cobalt (g/l) will remain in solution if V ml of CoSO4 solution with initial concentration is passed through a column filled with m g of cation exchanger. The total dynamic capacity under separation conditions is 1.6 mmol/g (molar mass equivalent is M(1/2CO2).
Option 2
m,g 5.0
V, ml 250