Is all a whole single question

The concentration of Copper(II) in a water sample (20ml) was determined by titration in the laboratory by reacting the copper ions with potassium iodide (KI) and then titrating the iodine produced with standardised sodium thiosulphate (Na2S2O3) via reactions (A) and (B). 2CuSO4+4KI2CuI+I2+2K2SO42Na2S2O3+I2Na2S4O6+2NaI Sodium thiosulphate was standardised using 10ml of potassium iodate (0.021M) via reactions (C) and (D): KIO3+5KI+3H2SO43K2SO4+3I2+3H2O2Na2S2O3+I2Na2S4O6+2NaI (i) Calculate the exact concentration of the sodium thiosulphate solution in the burette, given that 25.4ml was required to reach the endpoint. (ii) Calculate the concentration of Copper(II) in the water sample, given that 20.2ml of the standardized sodium thiosulphate solution was required to reach the endpoint. (iii) The EPA have set an Action Level of 1.3mgL1 for Copper(II) in water. Does the sample result calculated in (ii) above exceed this action level? (iv) Suggest one treatment process which could be implemented to reduce the copper concentration of a water body