(a) Suppose someone drops lots of PbS (s) into a freshwater

(a) Suppose someone drops lots of PbS(s) into a freshwater lake. Calculate [Pb2+(aq)] (mol/L). Ksp for PbS(s) is 8.9 × 10-29.
(b) The Platte River has a salinity of 0.079 g NaCl per L. Repeat the above calculation in this water. Assume the water has a density of 1.00 g cm-3.