Question

Too much chloride ion in drinking water can cause the following undesirable effects: salty taste . The EPA's Secondary Maximum Contaminant Level for chloride ion in drinking water is 250 mg/L.

(1) If 3.24×10⁴liters of water in a storage tank contains 31.2 grams of Cl^-, what is the contaminant level in ppm? ______ ppm
Assume that the density of the impure water is 1.00 g/mL.

(2) Is this level acceptable based on EPA guidelines? _________ acceptable or not acceptable

AND

A sample of an industrial waste water is analyzed and found to contain 37.7 ppb Cu⁺. How many grams of copper could be recovered from 1.28×10³ kg of this waste water?

_______grams Cu

Answer 1

1)

Mass of Cl^- = 31.2g = 31200mg

volume of water = 3.24×10⁴L  

concentration of Cl^- = (31200mg/3.24×10⁴L) × 1L = 0.963 mg/L

mg/L = ppm

Therefore

Concentration level of Cl^- in ppm = 0.963ppm

2)

Yes this level is acceptable

3)

1ppb = 1000ppm

37.7 ppb = 37700ppm

ppm = mg/kg

37700ppm = 37700mg/kg

Therefore

grams of copper could be recovared = (37700mg/1kg)×1280 kg )/1000 = 48256g