a) What do you call the difference between the amount of chlorine added to water and the amount of residual chlorine at the end of specified period of time. b) How many Kg of 61% calcium hypochlorite Ca(QCl)2 are required for 50mg/L dosage in a tank that is 33.5m in diameter (D) and has a water level (H) of 5.8m ? 2) How many lb/day of HTH (65\%) are required to treat 7 MGD of water and satisfy a 2.8mg/L demand as well as a 0.6mg/L residual? Answer HTH required =305.37lb/ day 3) In order to disinfect a sedimentation basin measuring 20 feet in width ,60 feet in length, and is 10 feet deep to obtain 50ppm would require how many pounds of 65% available HTH? AnswerHTHrequired=57.58lb 4) What should be the chlorinator setting in lb/day to treat a flow of 2MGD if the chlorine demand is 5mg/L and a chlorine residual of 0.8mg/L is desired? Answer Chlorinator setting =96.74lbs/ day 5) How many pounds of 65%HTH chlorine will be required to disinfect 400 feet of 8 -inch water main at 50ppm ? Note: volume =0.785d2h