Mixing natural tendency toward

Drinks mix office desks clutter decks of cards shuffle entropy is the natural tendency toward disorder. Entropy has also been called the tax that nature charges. Entropy has also been called the universal death sentence. But entropy is not just a philosophical construct or a pessimistic outlook. It is a real driver for physical processes and does indeed weigh in as a determinant in the fate of the universe. 

Solutions are homogeneous mixtures and can be gases, liquids, or solids. Two gases, for example, will mix in all proportions to give a gaseous solution, because gases are miscible in one another. Often one substance will dissolve in another only to a limited extent. The maximum amount that dissolves at equilibrium is the solubility of that substance. Solubility is explained in terms of the natural tendency toward disorder (say, by the mixing of two substances) and by the tendency to result in the... 

Boerhaave also brought together different genres of experiments on air to devise a consistent picture of its nature and operations. He was familiar with Boyle s and Mariotte s experiments with the air-pump, which characterized the elasticity of air, as well as with Hales s experiments on the fixation of air. On the one hand, this elastic medium functioned as an instrument of many chemical operations. On the other hand, air particles exhibited a tendency towards a union. The air fixed in bodies seemed to take up a very small space when divided into smaller particles of its proper substance, but it expanded considerably when these particles were collected together. Boerhaave s discussion of air, like the one on fire, is remarkable for the facility with which he mixed different genres of instrumental practices to create a coherent ontology of these supposedly elementary bodies. He discussed various effects... 

You may wonder why a solute dissolves in a solvent at all if the attraction for its own molecules is stronger than the solute-solvent attraction. The solution process, like all physical and chemical processes, is governed by two factors. One is energy, which determines whether a solution process is exothermic or endothermic. The second factor is an inherent tendency toward disorder in aU natural events. In much the same way that a deck of new playing cards becomes mixed up after it has been shuffled a few times, when solute and solvent molecules mix to form a solution, there is an increase in randomness, or disorder. In the pure state, the solvent and solute possess a fair de-... 

One factor determining solubility is Ihe natural tendency of subsfances to mix (the tendency of systems to move toward disorder). If fhis were all fhat was involved, however, we would expect substances to be completely soluble in one another. This is clearly not Ihe case. So what olher factors are involved As we saw in Section 13.1, tire relative forces of attraction among the solute and solvent molecules also play very important roles in the solution process. 

The simplest example of a molecular solution is one gas dissolved in another gas. Air, essentially a solution of oxygen and nitrogen, is an example. The intmnolecular forces in gases are weak. The only solubility factor of importance is the natural tendency for molecules to mix (the inclination toward disordCT). Giases are thCTcfore miscible. 

The reason that seawater draws water to itself is related to nature s tendency toward spontaneous mixing, which we discuss in more detail later in this chapter and in Chapter 17. For now, we simply observe that, unless it is highly unfavorable energetically. 

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