The results of a chlorine demand test is: Chlorine 0.2 0.4 dose mg/l Residual 0 chlorine mg/l 0.6 0.8 1.0 1.2 0.2 0.36 0.5 0.48 0.2 a.) Sketch the chlorine demand curve. (2 marks) 3 1.4 1.6 1.8 0.4 0.6 0.8 b.) What applied dosage is required to give a free chlorine residual of 0.3 mg/l? (3 marks)