Question

The maximum amounts of lead and copper allowed in drinking water are 0.015 mg/kg for lead and 1.3 mg/kg for copper. Express these values in parts per million.

a) 0.015 ppm, 1.3 ppm
b) 15 ppm, 1300 ppm
c) 15,000 ppm, 130,000 ppm
d) 0.0015 ppm, 0.13 ppm

Answer 1

The maximum allowable concentrations of lead and copper in drinking water, 0.015 mg/kg and 1.3 mg/kg, are equivalent to 0.015 ppm and 1.3 ppm respectively.

Step-by-step explanation:

The question asks to convert the maximum allowable concentrations of lead and copper in drinking water, given in mg/kg, into parts per million (ppm). Since 1 mg/kg is equivalent to 1 ppm (because 1 mg is a millionth of a kilogram), the conversion is straightforward. The limit for lead is given as 0.015 mg/kg, so this is directly equal to 0.015 ppm. Similarly, the limit for copper is given as 1.3 mg/kg, which equals 1.3 ppm. Therefore, the correct answers are a) 0.015 ppm, 1.3 ppm.