Experimental Techniques Used for Studying Solution Reactions

Experimental Techniques Used for Studying Solution Reactions 

The approaches to studying reaction kinetics in the liquid phase are analogous to those in the gas phase, that is, the use of various spectroscopic techniques to follow the loss of one reactant in the presence of a large excess of the second reactant. UV-visible spectroscopy is a primary tool for following both stable species and radicals in solution. 

As discussed in Chapters 7, 8, and 9, there are a number of free radical species whose reactions in the aqueous phase drive the chemistry of clouds and fogs. These include OH, HOz, NO-, halogen radicals such as Cl2, sulfur oxide radicals, and R02. Generation of these radicals in the liquid phase for use in kinetic 

To generate other free radicals, OH can be reacted with other species (e.g., see Zellner and Herrmann, 1995). For example, 

In the case of the chlorine reactions, the involvement of H+ in the second step means that these reactions are efficient sources of chlorine atoms only at a pH less than about 4. Br can be converted to Br atoms in reactions analogous to those for chlorine, but in this case, generation of atomic bromine occurs up to a pH of about 11 (Zellner and Herrmann, 1995). 

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