A 200 g sample of sediment is analyzed for the pollutant trichloroethylene (TCE). The analysis indicates that the sample contains 0.26 mg of TCE.

a. What is the TCE concentration in ppm?

b. What is the TCE concentration in mg/L if the density of sediment is 0.72 g/cm3

2. The limit to the level of sulfur dioxide (SO2) in ambient air, set by the Turkish National Ambient Air Quality Standards is 350 g/m3 . The ambient air in an industrial area was anaylzed and the analysis indicated that 10 L of gas contained 1.0 x 10-7 mole of SO2. Do the appropriate calculation and decide whether the air meets the national air quality standards or not.

3. Consider a water sample with a Ca2+ concentration of 55 mg/L and a Mg2+ concentration of 35 mg/L. Calculate the total hardness, expressed as mg/L CaCO3.

4. Regulations require that the total concentration of nitrite (NO2 - ) and nitrate (NO3 - ) be below 10.0 mg/l as N to avoid methemoglobinemia, or blue-baby syndrome, which can be fatal. Nitrite and nitrate, however, are often elevated in groundwater in agricultural regions due to commonly used nitrogen fertilizers. An analyst reports that the concentration of NO2 - is 11.5 mg/L and NO3 - is 37.2 mg/L in a groundwater sample from a farming region. What is the concentration of NO2 - and NO3 - expressed as mg/L as N? Does the water meet the standards?

5. Humic acids are complex organic molecules produced when plants, fats, excrement and organisms decompose oxidatively in the environment. Humic acid has the average chemical formula C187H186O89N9S. What is the TOC of a water sample that contains 4.2 mol/L of humic acid?