Particles of gas

Particles of gas travel fast and in straight lines, unless they collide. 

In summary, we realize how each particle of gas has enormous kinetic energy and are separated widely. Yet, like popcorn in a popcorn maker, these particles cannot be classed as wholly independent, one from another, because they collide. They collide... 

Vacuum gages can be either direct or indirect reading. Those that measure pressure by calculating the force exerted by incident particles of gas are. direct reading, while instruments that record pressure by measuring a gas property that changes in a predictable manner with gas density are indirect reading. 

Thus, it is not the absolute value of D, but its ratio with k that determines the character of the phenomena. Convection blurs the effect in convective motion the particles of gas which carry quantities of material and heat are in the ratio of the concentration to the product of the specific heat and temperature, which corresponds to equality of the effective (related to the gas motion) coefficients of diffusion and thermal diffusivity. In all cases radiation from the surface of the catalyst lowers its temperature Tr. 

As justification for the third point we cite some typical figures we define the relaxation time of a process in the gas as the ratio of the width of the zone of temperature change to the velocity of the gas. In other words, we define the relaxation time as the time during which a certain particle of gas travels from the interface to the place where the reaction ends. 

Detonation, as described earlier, is a process where upon a matrix of uniform particles of gas and solid forms a pressure wave. The pressure wave is what causes the bulk of destruction. However, it should be noted that detonation is a completely different process then deflagration and combustion. As previously stated, compounds that detonate must poses certain functional groups. These functional groups are initiated by molecular shocks generated by blasting caps, detonators, and/or boosters. Of coarse not all explosives need to be initiated by blasting caps, detonators, and/or boosters for example, primary explosives (which you will learn much about shortly) can be detonated under relatively easy means by sparks, heat, friction, percussion, fire, and shock. 

Eq. (8) states that the accumulation of mass in both free and adsorbed form (LHS) is balanced by the diffusion rate into the particle of gas (first term in RHS) and the adsorbed species (second term in RHS). The diffusion rate of adsorbed species in particle is related to the observed adsorbed concentration (Eq. 6) so that the effect of size exclusion (Eq. 5) has... 

How does temperature affect the behavior of a gas You know from Chapter 10 that at higher temperatures, the particles in a gas have greater kinetic energy. They move faster and collide with the walls of the container more often and with greater force, so the pressure rises. If the volmne of the container and the munber of particles of gas are not changed, the pressure of a gas increases in direct proportion to the Kelvin temperature. 

We return now to the calculation of the most probable distribution of the molecules in the individual cells of the box. A definifce distribution is described by the numbers in the various cells 2.. ., n their sum is of course equal to the number of particles of gas in the box ... 

We may wish, for example, to know the probability of finding a gas molecule at a definite spot in the box within which we suppose the gas to have been enclosed. If no external forces act on the molecules, we shall be unable to give any reason why a particle of gas should be at one place in the box rather than at another. Similarly, in this case there is no assignable reason why a particle of the gas should move in one direction rather than in another. We therefore introduce the following hypothesis, the principle of molecular chaos For the molecules of gas in a closed box, in the absence of external forces, all positions in the box and all directions of velocity are equally probable. 

The movement of the glass bowl by the experimenter is irrelevant, the particles in a portion of matter move independently, the higher the temperature the more the movement. What is the substance between the particles of gas or steam In the model one finds air between the spheres an irrelevant item In reality there is nothing between the particles of a gas. 

To this point we have assumed, in both theory and calculations, that all gases behave as ideal gases. However, in reality there is no such thing as an ideal gas. As we noted at the beginning of this section, the ideal gas is a model (a very useful one) that describes the behavior of individual atoms and molecules this behavior translates to the collective properties of measurable quantities of these atoms and molecules. Limitations of the model arise from the fact that interactive forces, even between the widely spaced particles of gas, are not totally absent in any sample of gas. 

Therefore, we can calcnlate the partial pressure of B if we know the mole fraction of B and the total pressure in each container. Because the containers all have the same volnme and the same temperature, the pressure in each container will be directly proportional to the moles of gas (or particles of gas). We catmot calculate the pressure directly because the volume and temperature are not known, bnt the pressures will be proportional to the number of particles in each container (9,12, and 15, respectively). Let s assume that the pressures are in units of atmospheres (i) 9 atm, (ii) 12 atm, (iii) 15 atm. 

The volume of bulb (c) is the same as bulb (a), but there are 12 particles in (c) while there are 9 particles in (a). The pressure is directly proportional to the number of moles of gas (or particles of gas) at the same temperature and volume. 

There are 15 particles of gas A and 15 particles of gas B in the container. Therefore, the partial pressnre of each gas will be half the total pressure of 5.3 atm. 

If the temperature of a sample of gas is increased, the average kinetic energy of the particles of gas increases. This means that the speeds of the particles Increase. If the particles have a higher speed, they hit the walls of the container more frequently and with greater force, thereby increasing the pressure. 

The numbers of moles on both sides of the arrow are the same - three moles of reactants and three moles of product are shown. But the state symbols show the reaction produces one mole of gas. There are many more ways of arranging the particles of gas than in the solid state. To understand this, compare the number of ways the same sand grains can be arranged in a sandcastle (one way) and in a random pile of sand (many ways) Figure 5.13. 

By considering a square pile of shot Dalton concluded that the single particle at the apex distributes its pressure among all the shots in a low er layer, and so the particle of gas distributes its pressure equally amongst every successive horizontal stratum of particles of water downwards till it reaches the sphere of influence of another particle of gas . The numbers of particles in successive layers of the pile are, i, 4, 9, 16,... i.e. i, 2, 3, 4. .. . Suppose one particle presses on the surface of the water and let the distance of the particles of gas from each other be to those of water as 10 to i ... 

During compression, the gas particles, which are initially very far apart (assumption 1), are crowded closer together. The volume of a given sample of a gas can be greatly decreased. Steel cylinders containing gases under pressure are widely used in industry. When they are full, such cylinders may contain more than 100 times as many particles of gas as nonpressurized containers of the same size could contain. 

---