Chemistry Hw due in two hours

CE 441 Environmental Engineering Homework #2

(Due 02/13/2013)

1. Calculate the molarity and normality of (a) 100 mg/L of H2SO4 and (b) 100

mg/L of HCl. 2. Find mg/L of (a) 0.02 N Ca++ and (b) 0.5 M HCO3-. 3. The solubility product of calcium fluoride (CaF2) is 3.45 x 10-11 M3. Will a

fluoride concentration of 1.0 mg/L be soluble in a water sample containing 200 mg/L of calcium?

4. If 10 mg of H2SO4 is added to 1L of water, what is the final pH? What amount of NaOH, in mg, would be required to neutralize this acid solution?

5. Calculate the pH of a water sample at 25 oC that contains 0.62 mg/L of carbonic acid. Assume that [H+] = [HCO3-] at equilibrium and neglect dissociation of water.

6. Convert the following from mg/L as the ion to mg/L as CaCO3: (a) 100 mg/L Ca++ (b) 100 mg/L CO2 (c) 100 mg/L HCO3- (d) 100 mg/L CO3=

7. Calculate the “approximate” alkalinity (in mg/L as CaCO3) of water containing 120 mg/L of bicarbonate ion and 10 mg/L of carbonate ion.

8. Convert (a) 20 mg/L NO3- and (b) 20 mg/L NH3 in mg-N/L.