Temperature change collision theory

This universality is peculiar for the high-temperature approximation, which is valid for //J < 1 only. For sufficiently high temperature the quantum theory confirms the classical Langevin theory result of J-diffusion, also giving xj = 2xE (see Chapter 1). This relation results from the assumed non-adiabaticity of collisions and small change of rotational energy in each of them ... 

Although there is a great deal of evidence to show that temperature changes affect reaction rates, there is no single theory that explains why. There are two main theories that together explain the relationships between temperature and rates. Neither theory on its own is sufficient to explain the relationship. The two theories are the collision theory and the transition-state theory. 

Temperature has adefinite effect on re action rate, but the reasons for the changes are not completely understood. The two theories that describe this relationship are the collision theory and the transition-state model. Collision theory proposes that increases in temperature increase reaction rates by increasing the number of collisions that occur between particles and by increasing the kinetic energy that particles possess when they collide. 

Explain, in terms of collision theory, why changes in temperature and in pressure and the addition of a catalyst alter the rate of a gas phase reaction. 

The effect of a catalyst on the rate equation is to increase the value of the rate constant. Table 16.11 summarizes the changes that affect the rate of reaction and the rate constant. Rate constants are unaffected by changes in concentration and are only affected by temperature (as described by the Arrhenius equation) or the presence of a catalyst, which provides a new pathway or reaction mechanism. Rates increase with concentration and pressure (if gaseous reactants are involved), which can be accounted for by simple collision theory (Chapter 6). 

Temperature has a definite effect on reaction rate, but the reasons for the changes are not completely understood. The two theories that describe this relationship are the collision... 

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