Question

If a 150 mL sample of water from a lake is found to contain 1.7 μg of arsenic (As), what is the concentration of arsenic in the sample in parts per billion (ppb)?

Answer 1

9 xio We know, Parit & per billion (PP.b) = Mass8 of Solute (8) volume of solution (mL) Here, in this problem given Maoiss of crisenic (A%) = 1.7 ug = 1.7x10 Asl ug = 100g) volume of solution = 150 ml Now, parito per billion (ppb) = Masks of Arsenic (AB) in g) volume of solution (in mL) 1.7x156 og X10 9 Xio 150 11 1700 150 = 11 33 ppb therefore, the concentration of arosenic in the sample in parte per billion (ppb) ij8 11:33 ppb.