Question:
Most community water supplies have 0.5 ppm of chlorine added for purification. ...?

Most community water supplies have 0.5 ppm of chlorine added for purification. What mass of chlorine must be added to 132.0 L of water to achieve this level?

Answer: divide the grams by 0.5 million... that's not right 'coz you'll not end up with mass chlorine

If you take the volume of chlorine into account, it's going to be a little hard to solve:0.5mg solute/ 1 L solution = mg chlorine / (132.0 L + L chlorine)

...so I'll just give you the approximate answer:0.5 ppm = 0.5 mg / L0.5 mg/L * 132.0 L = 66 mg chlorine (20+mL)