Collisions between gas particles

Collision between gas particles and between gas particles and the walls of the container are elastic. This means that the total kinetic energy of the gas particles is constant as long as the temperature is constant. 

Boyle s law (P oc /V) Gas pressure is a measure of the number and forcefulness of collisions between gas particles and the walls of their container. The smaller the volume at constant n and T, the more crowded together the particles are and the greater the frequency of collisions. Thus, pressure increases as volume decreases (Figure 9.11a). 

Collisions between gas particles or collisions with the walls of the container are perfectly elastic. None of the energy of a gas particle is lost when it collides with another particle or with the walls of the container. 

Particle motion Gas particles are in constant, random motion. Particles move in a straight line until they collide with other particles or with the walls of their container, as shown in Figure 13-1. Collisions between gas particles are elastic. An elastic collision is one in which no kinetic energy is lost. Kinetic energy may be transferred between colliding particles, but the total kinetic energy of the two particles does not change. 

Boyle s law relates pressure and volume of a gas, and Charles s law states the relationship between a gas s temperature and volume. What is the relationship between pressure and temperature Pressure is a result of collisions between gas particles and the walls of their container. An increase in temperature increases collision frequency and energy, so raising the temperature should also raise the pressure if the volume is not changed. 

Because both neon and argon gases expand to fill the whole container, the volume for the argon gas and the volume for the neon gas are equal. Similarly, because the collisions between gas particles in the same container will lead the gases to have the same temperature, the temperatures for the argon gas and the neon gas are also equal. Therefore, the common RTIV can be factored out to yield a simplified form of the equation. 

Increased rate of collision between gas particles and liquid... 

M FIGURE 11.8 Pressure Since pressure is a result of collisions between gas particles and the surfaces around them, the amount of pressure increases when the number of particles in a given volume increases. 

Figure 5.14 Pressure arises from countless collisions between gas particles and walls.

Collisions between gas particles and between particles and container walls are elastic collisions. An elastic collision is one in which there is no net loss of total kinetic energy. Kinetic energy is transferred between two particles during collisions. However, the total kinetic energy of the two particles remains the same as long as temperature is constant. 

Boyle s Law At a constant temperature, the pressure exerted by a gas depends on the frequency of collisions between gas particles and the container. If the same number of particles is squeezed into a smaller space, the frequency of collisions increases, thereby increasing the pressure. Thus, Boyle s law states that at constant temperature, the pressure and volume of a gas are inversely related. In mathematical terms, this law is expressed as follows. 

A popular misconception says a molecule in the gas phase travels faster than when in a liquid. In fact, the molecular velocities will be the same in the gas and liquid phases if the temperatures are the same. Molecules only appear to travel slower in a liquid because of the large number of collisions between its particles, causing the overall distance travelled per unit time to be quite short. 

As a direct consequence of the large intermolecular separations, we can safely say no interactions form between the molecules in ammonia gas. The molecules are simply too far apart. We saw in the previous chapter how the property known as pressure is a macroscopic manifestation of the microscopic collisions occurring between gas particles and, say, a solid object such as a container s walls. But the gas particles can also strike each other on the same microscopic scale we say the resultant interactions between molecules are intermolecular. 

Boyle s law describes the relationship between the volume and the pressure of a gas when the temperature and amount are constant. If you have a container like the one shown in Figure 8.3 and you decrease the volume of the container, the pressure of the gas increases because the number of collisions of gas particles with the container s inside walls increases. 

The effect of the collisional force due to the impact of particles should be included when accounting for the motion of a particle except in a very dilute gas-solid flow situation. Basic mechanisms of collision between two particles or between a particle and a solid wall are discussed in Chapter 2. The collisional force between a particle and a group of neighboring particles in a shear suspension is discussed in 5.3.4.3. In a very dense system where particle collisions dominate the flow behavior, collisional forces can be described by using kinetic theory, as detailed in 5.5. The key equations derived in other chapters pertaining to the collisional forces can be summarized in the following. 

The plasma is created by an electrical field between both parallel plates (see figure), ionizing the gas volume inbetween. In a plasma, the energy is transferred by collisions between all particles. Due to their smaller mass, the energy of the electrons increases much faster than the energy of the heavier ions. This means that mainly the electrons are responsible for the ionization processes and the formation of reactive free radicals. The big energy difference between electrons and ions is reflected in the respective temperatures the electron temperature of a typical plasma is about... 

The particles in a sound field, however, behave in a peculiar manner which is not quite so simple. St. Clair points out that at a frequency of 5000 cycles, particles of 0.5 n or smaller (density = 1.5) have an amplitude and velocity the same as that of the surrounding gas, while particles of 10 p will scarcely vibrate at all. The intermediate sizes will pulsate out-of-phase with the pulsations of the gas stream. Thus particles 2 u will have an amplitude of 0.87 that of the gas and will be about 30 deg out-of-phase. It has been suggested by Brandt and Hiedemann that the flocculating effect is due to the increased number of collisions between the particles due to the kinetic energy imparted to them. However, as St. Clair points out, this cannot be the sole factor since flocculation is observed at a few hundred cycles for which the suspended particles remain stationary. 

The type of flow of a fluid through a tube depends on the rate of flow. At low speeds it is laminar, where all the particles are moving parallel to each other as in a gently flowing stream. As the speed increases a point is reached when the flow is turbulent. The point at which this occurs is determined by the shape of the containing vessel or tube. The above discussion refers to a fluid, where collisions between the particles themselves are more important than collisions between the particles and the vessel or tube walls, and applies to a gas where the mean free path is small compared... 

When a solid reacts with a liquid or a gas the collisions between the particles must occur at the surface of the solid. If the solid is subdivided (broken up) there will be more of its surface exposed to the other reactants - so there will be more collisions per second at the surface, resulting in an increase in the reaction rate. 

Q Kinetic energy may be transferred between gas particles during an elastic collision. What influence do gas particles have on each other between collisions ... 

The collisions between the particles of the gas are considered to be perfectly elastic, which means that, although kinetic energy may be transferred from one particle to another, the net kinetic energy is conserved. 

The particles in a gas are constantly colliding with the walls of the container and with each other. Because of these collisions, the gas particles are constantly changing their direction of motion and their velocity. In a typical situation, a gas particle moves Objective 3 a very short distance between collisions. For example, oxygen, O2, molecules at normal temperatures and pressures move an average of 10 m between collisions. 

With increasing density of the electrons in the plasma, in addition to the binary electron collisions with gas particles, the Coulomb interaction between the electrons becomes more and more important, and its impact on the kinetics of the electrons has to be considered. Finally, if this interaction process dominates... 

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