1. What role does coagulation play in water treatment? Why is it necessary to add ferric chloride? 2.During the mixing step, briefly discuss why gentle mixing of the solution is necessary after the addition of ferric chloride? How does this impact the next step of sedimentation? 3. Although the water which has been filtered looks clean, why do we need to take the extra step of disinfecting it? 4. Most of us have had a glass of water from a Brita® pitcher. What is inside of a Brita® filter cartridge and what does it filter out? What doesn’t it filter out? 5. Last year, the average American used 167 disposable water bottles (16.9 oz or 0.132 gallons). If the cost of 1 gallon of tap water in Philadelphia is approximately 7 cents, how much money could be saved by drinking tap water if we assume the cost of 1 bottle of water is $1.00?