Example 5-1 Situation : A small water distillation plant is to be built for a remote coastal outpost on a shallow marine bay and having no access to fresh water. It is planned that ethylene will be used as fuel for the plant. Question(s) : Assuming 90% efficiency, how much seawater at 20 oC can be converted to steam at 100 oC by each cubic meter of C 2 H 4 gas burned?

Example 5-2 Situation : It is often helpful when assessing the stavility of various chemical compounds to know the oxidation states in which the atoms comprising those compounds exist. Question(s) : Determine the oxidation states of the atoms of the following compounds of sulfur : (a)Na 2 SO 4 ; (b)FeSO 4 ; (c)H 2 SO 4 ; (d)H 2 SO 3 ; (e)H 2 S.

Example 5-3 Situation : An application of the interrelationships shown in Figure 5-1 for characterization of the pH domains of natural freshwater systems. Question(s) : Demonstrate how the pH values of CO2-driven, CO2-CO32—balanced, and CO32- -driven systems pictured in Figure 5-1 can be determined by analysis of the information presented. Based on the results of this demonstration, what dominant range of pH would be predicted for most natural aquatic systems?

Example 5-4 Situation : We wish to determine the solubility of Fe(II) as a function of pH in an aqueous carbonate system, in a manner similar to that presented in Figures 5-2 and 5-3 but have information on the solubility constants for only Fe 2 + with respect to Fe(OH) 2 (s) and FeCO 3 (s). Question(s) : Calculate solubility constants for the {Fe(OH)}+ species of soluble iron with respect to each of the two solid phases involved: (a)ferrous hydroxide and (b)ferrous carbonate.