Question

A 62.9 g sample of ground water is found to have a lead concentration of 13.97 ppm. Calculate the mass of lead in the sample in milligrams.

Answer 1

0.879 mg

Step-by-step explanation:

To solve this problem we need to use the definition of ppm:

• ppm = μg solute / g solution

With the above information in mind we can calculate the micrograms of lead using the concentration (13.97 ppm) and mass of solution (62.9 g):

• μg lead = 13.97 ppm * 62.9 g

• μg lead = 878.713 μg

Finally we convert μg to mg:

• 878.713 μg *
  `(1mg)/(1000ug)` = 0.879 mg of lead