Chapter 1

Average ozone concentrations in jakarta, Indonesia have been reported to be \(0.015 \mathrm{mg} \mathrm{m}^{-3}\) and those in Tokyo, lapan are \(20 \mathrm{ppbv}\). What is the approximate ratio of these two values, when expressed in the same units?

The principal anion and cation in Lake Huron, one of the Great Lakes in North America, are respectively hydrogen carbonate and calcium. The concentration of the former is approximately \(1.05 \mathrm{mmol} \mathrm{L}^{-1}\). Calculate the mass of solid calcium carbonate that would remain if \(250 \mathrm{~mL}\) of Lake Huron water is evaporated to dryness.

The concentration of titanium in the South Pacific Ocean, near the island nation of Fiji, has been found to be approximately \(3.0 \times 10^{-9} \mathrm{~mol} \mathrm{~L}^{-1}\). Calculate the concentration in ppm, ppb, or ppt as appropriate,

The concentration of copper in the surface organic layer of a forest soil is \(37 \mathrm{ppm}\), and in the underlying mineral layer it is 17 ppm. The bulk densities of these two layers are \(0.36\) and \(1.22 \mathrm{gmL}^{-1}\) respectively, The very low density of the surface material is because it consists in large part of partially degraded organic material and there is very little of the heavier mineral matter. Which of these two layers has the larger amount of copper per unit volume?

The concentration of cadmium in the top \(15 \mathrm{~cm}\) of soil in a field (often called the plow layer) can be estimated by taking a representative sample, dissolving the soil and analysing it by atomic absorption spectroscopy with electrothermal atomization. The concentration is found to be \(0.78 \mathrm{ppm}\). Suppose that dewatered (solid) sewage sludge containing \(22 \mathrm{ppm}\) cadmium is added at the rate (mass per area) of 3 tha \(^{-1}\). Assuming sludge is well mixed within the plow layer, calculate the new average concentration of cadmium within this part of the soil. The bulk density of the soil is \(1.1 \mathrm{gmL}^{-1}\).