General Properties of Solutions

The term solution is used in chemistry to describe a system in which one or more substances are homogeneously mixed or dissolved in another substance. A simple solution has two components a solute and a solvent. The solute is the component that is dissolved or is the least abundant component in the solution. The solvent is the dissolving agent or the most abundant component in the solution. For example, when salt is dissolved in water to form a solution, salt is the solute and water is the solvent. Complex solutions containing more than one solute and/or more than one solvent are common. 

The three states of matter—solid, liquid, and gas—give us nine different types of solutions solid dissolved in solid, solid dissolved in liquid, solid dissolved in gas, liquid dissolved in liquid, and so on. Of these, the most common solutions are solid dissolved in liquid, liquid dissolved in liquid, gas dissolved in liquid, and gas dissolved in gas. Some common types of solutions are listed in Table 14.1. 

A true solution is one in which the particles of dissolved solute are molecular or ionic in size, generally in the range of 0.1 to 1 nm (10 to 10 cm). The properties of a true solution are as follows  

A mixture of two or more components—solute and solvent—is homogeneous and has a variable composition that is, the ratio of solute to solvent can be varied. 

The solute remains uniformly distributed throughout the solution and will not settle out with time. 

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Aqueous electrolyte solutions have been a subject of determined studies for over a century. Numerous attempts were made to construct theories that could link the general properties of solutions to their internal structure and predict properties as yet nnknown. Modem theories of electrolyte solutions are most intimately related to many branches of physics and chemistry. The electrochemistry of electrolyte solutions is a large branch of electrochemistry sometimes regarded as an independent science. 

In the past, the basic experiment used to study the general properties of solutions was the measurement of the vapour pressure lowering of the solvent (Raoult 1890). But this method which is, in general, efficient is not really useful when the vapour pressure reduction is small. In such situations, it has been replaced by another method which is quite similar it consists in measuring the osmotic pressure of the solution with respect to the solvent. 

To study the most general properties of solutions of linear polymers, only two renormalization factors, 0(z) and X l (z), are needed. The renormalization condition which determines Ii(z) is... 

GENERAL PROPERTIES OF SOLUTIONS AND THE GIBBS-DUHEM EQUATION... 

Recent studies in our laboratory demonstrated that similar interactions between the transport carrier proteins and the linear electron transfer chain exists in Rps. sphaeroides and also in E. coli. This indicates that a regulation by electron transfer is a general property of solute transport systems in bacteria. 

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