This figure shows a breakpoint chlorination curve for a water supply source. Identify the chlorine dose or the range of doses where the following statements apply and support your idea with reasons:

a) The free Cl residual is 0.5 mg/L.

b) The combined Cl residual is 2.0 mg/L.

c) When a small increment of chlorine is added, most of it undergoes no redox reaction.

d) When a small increment of chlorine is added, most of it reacts with N-containing compounds.

Problem 4 (20 pts) 2.5 2.0 1.5 Cl, residual (mg/L) v 1.0 0.5 0.0 0 1 2 3 4 5 Cl, dose (mg/L) This figure shows a breakpoint chlorination curve for a water supply source. Identify the chlorine dose or the range of doses where the following statements apply and support your idea with reasons: a) The free Cl residual is 0.5 mg/L. b) The combined Cl residual is 2.0 mg/L. c) When a small increment of chlorine is added, most of it undergoes no redox reaction. d) When a small increment of chlorine is added, most of it reacts with N-containing compounds