Problem 3. A surface water sample contains 20g (micro-grams)/L of lead ions (Pb2+). a) Calculate the molarity of Pb2+ ions as mole/L in the sample. (5p) b) Calculate the normality of Pb2+ as eq.mol/L ions in the sample. (5p) c) Calculate the Pb2+ concentration as ppm in the surface water sample. (5p) Molecular weights (g/mole): Pb=207.2 Density of water (w)=1g/cm3