Kinetic Molecular Theory of matter

The Kinetic Molecular Theory of matter attempts to describe all the states of matter and the conversion between the states by considering the structures of molecules comprising matter and how those molecules interact. There are three commonly encountered states of matter solids, liquids, and gases. There are a few other states of matter, such as plasmas, but these are encountered only under extremely high energy conditions. Therefore, we will restrict our conversation to the more mundane states. 

Rationalize the defining characteristics of the states of matter in terms of intermolecular forces and the kinetic molecular theory of matter. 

Demonstrate an understanding of the kinetic molecular theory of matter. 

SECTION 1 The Kinetic-Molecular Theory of Matter KEY TERMS ... 

There are general relationships of transport phenomena based on phenomenological theory, i.e., on the correlations between macroscopically measurable quantities. The molecular theories explain the mechanism of transport processes taking into account the molecular structure of the given medium, applying the kinetic-statistical theory of matter. The hydrodynamic theories are also applied especially to describe - convection. 

LIQUIDS OR SOLIDS IN MANY WAYS. MOLECULAR MOTION IN GASES IS TOTALLY RANDOM, AND THE FORCES OF ATTRACTION BETWEEN GAS MOLECULES ARE SO SMALL THAT EACH MOLECULE MOVES EREELY AND ESSENTIALLY INDEPENDENTLY OF OTHER MOLECULES. SUBJECTED TO CHANGES IN TEMPERATURE AND PRESSURE, GASES BEHAVE MUCH MORE PREDICTABLY THAN DO SOLIDS AND LIQUIDS. ThE LAWS THAT GOVERN THIS BEHAVIOR HAVE PLAYED AN IMPORTANT ROLE IN THE DEVELOPMENT OF THE ATOMIC THEORY OF MATTER AND THE KINETIC MOLECULAR THEORY OF GASES. 

The answer is yes and we will digress a bit at this point to introduce these concepts as we did earlier in the chapter. The temperature and pressure conditions that govern physico-chemical behavior of liquids are defined in terms of thermodynamics. The Gibbs Phase Rule is a direct outcome of the physical chemistry of changes in the state of matter. The phase rule helps to interpret the physico-chemical behavior of solids, liquids, and gases within the framework of the kinetic-molecular theory of phase equilibria. 

Gases, the subject of this chapter, are simpler than liquids and solids in many ways. Molecular motion in gases is totally random, and the forces of attraction between gas molecules are so small that each molecule moves freely and essentially independently of other molecules. Subjected to changes in temperature and pressure, it is easier to predict the behavior of gases. The laws that govern this behavior have played an important role in the development of the atomic theory of matter and the kinetic molecular theory of gases. 

In the chapter States of Matter, you read about the kinetic-molecular theory, which is based on the idea that particles of matter are always in motion. In this section, you will study the implications of the kinetic-molecular theory of gases. 

For a quantitative description of the behavior of gases, we will employ some simple gas laws and a more general expression called the ideal gas equation. These laws will be explained by the kinetic-molecular theory of gases. The topics covered in this chapter extend the discussion of reaction stoichiometry from the previous two chapters and lay some groundwork for use in the following chapter on thermochemistry. The relationships between gases and the other states of matter— liquids and solids—are discussed in Chapter 12. 

Kinetic molecular theory first made a name for itself when scientists attempted to explain and predict the properties of gases and, in particular, how those properties changed with varying temperature and pressure. The idea emerged that the particles of matter within a gas (atoms or molecules) undergo a serious amount of motion as a result of the kinetic energy within them. 

It is worth noting at this point that the various scientific theories that quantitatively and mathematically formulate natural phenomena are in fact mathematical models of nature. Such, for example, are the kinetic theory of gases and rubber elasticity, Bohr s atomic model, molecular theories of polymer solutions, and even the equations of transport phenomena cited earlier in this chapter. Not unlike the engineering mathematical models, they contain simplifying assumptions. For example, the transport equations involve the assumption that matter can be viewed as a continuum and that even in fast, irreversible processes, local equilibrium can be achieved. The paramount difference between a mathematical model of a natural process and that of an engineering system is the required level of accuracy and, of course, the generality of the phenomena involved. 

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