Precipitation reactions molecular depiction

Problem The molecular views below depict reactant solutions for a precipitation reaction (with ions shown as colored spheres and water omitted for clarity) ... 

It has been also reported a study on the threading process of a a - cyclodextrin (a-CD) and polyethylene glycol (PEG), as a function of temperature and solvent composition. This reaction produces a polyrotaxane that eventually precipitates and forms a thick gel. Ceccato et al. [46] have proposed a molecular model for the interpretation of the temperature and solvent composition effect on the threading process. According of this model, the reaction can be depicted as a five - step phenomenon that mainly depend on the threading and sliding of a-CD and PEG. The transition... 

In the description of the refining of aluminum, the molecular scale depiction of precipitation was not included. Use the web to determine which chemicals are involved in the precipitation process and draw a molecular scale drawing of this reaction. 

The rate at which sulfur dioxide, released into the atmosphere, becomes oxidized to the +6 oxidation state to form sulfuric acid depends on the following conditions humidity, the amounts of dust particles, and the concentrations of transient radicals present, for example OH. Sulfur dioxide does not react directly with molecular oxygen and/or the water vapour in the air. Some of the principal mechanisms identified as contributing to its oxidation are outlined in this section and depicted in Figure 5.1. These reactions proceed slowly, the half-lives may be several hours or days, during which the sulfur may travel in moving air masses (wind) for hundreds of kilometres from the point of release. The sulfuric acid, mainly dissolved in raindrops, may then be precipitated to cause pollution at areas remote from the point of generation and predominantly downwind. 

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