Molecules average kinetic energy

Another way to observe the nonideal behavior of gases is to lower the temperature. Cooling a gas decreases the molecules average kinetic energy, which in a sense deprives molecules of the drive they need to break from their mutual attraction. 

Maxwell found that he could represent the distribution of velocities statistically by a function, known as the Maxwellian distribution. The collisions of the molecules with their container gives rise to the pressure of the gas. By considering the average force exerted by the molecular collisions on the wall, Boltzmann was able to show that the average kinetic energy of the molecules was... 

There would remain some very small residual motion of the pendulum due to the air molecules striking it at random (Brownian motion), but that does not count in the game of perpetual motion. In the condition of residual motion, the pendulum is just another (big) molecule sharing equally in the average kinetic energy of all the individual air molecules. In other words, the pendulum eventually comes to thermal equilibrium with the air. 

The kinetic theory is based upon the premise that if two gases are at the same temperature, the molecules of the gases have the same average kinetic energy. The ability of this kinetic theory to explain Avogadro s Hypothesis is one of its most important successes. 

The importance of the root mean square speed stems from the fact that is proportional to the average kinetic energy of the molecules, [Pg.284]

Could neutrons be used for diffraction studies of molecules The average kinetic energy of neutrons in a beam at a temperature T is kT, where k is Boltzmann s constant. What temperature is needed to achieve a wavelength of 100. pm for a neutron Refer to Major Technique 3 on x-ray diffraction, which follows this set of exercises. 

The average kinetic energy expressed by Equation is kinetic energy per molecule. We find the total kinetic energy ( kinetic molar) of one mole of gas molecules by multiplying Equation by Avogadro s number ... 

C05-0115. Consider two gas bulbs of equal volume, one filled with H2 gas at 0 °C and 2 atm, the other containing O2 gas at 25 °C and 1 atm. Which bulb has (a) more molecules (b) more mass (c) higher average kinetic energy of molecules and (d) higher average molecular speed ... 

A substance exists in a condensed phase when its molecules have too little average kinetic energy to overcome intermolecular forces of attraction. 

A gas condenses to a liquid if it is cooled sufficiently. Condensation occurs when the average kinetic energy of motion of molecules falls below the value needed for the molecules to move about independently. Thus, the molecules in a liquid are confined to a specific volume by intermolecular forces of attraction. Although they cannot readily escape, liquid molecules remain free to move about within the liquid phase, hi this behavior, liquid molecules behave like the molecules of a gas. The large-scale consequences of the molecular-level properties are apparent. Like gases, liquids are fluid, so they flow easily from place to place. Unlike gases, however, liquids are compact, so they cannot expand or contract significantly. 

B all gas molecules have the same average kinetic energy at the same temperature... 

Returning to our definitions in Chapter 3, temperature is a measure of the average kinetic energy of the molecules in a system. This means that the higher the temperature, the more movement in the polymer chains. Taking this one step further, the greater movement reduces... 

The average kinetic energy of the gas molecules is directly proportional to the absolute temperature of the gas. 

Postulate 1 means that the molecules move in any direction whatever until they collide with another molecule or a wall, whereupon they bounce off and move in another direction until their next collision. Postulate 2 means that the molecules move in a straight line at constant speed between collisions. Postulate 3 means that there is no friction in molecular collisions. The molecules have the same total kinetic energy after the collision as before. Postulate 4 concerns the volume of the molecules themselves versus the volume of the container they occupy. The individual particles do not occupy the entire container. If the molecules of gas had zero volumes and zero intermolecular attractions and repulsions, the gas would obey the ideal gas law exactly. Postulate 5 means that if two gases are at the same temperature, their molecules will have the same average kinetic energies. 

If two different gases are at the same temperature, which of the following must also be equal (a) Their pressures, (b) their average molecular velocities, or (c) the average kinetic energies of their molecules. 

Ans. No. The kinetic molecular theory states that the average kinetic energy is related to the temperature, not the velocity or kinetic energy of any one molecule. The velocity of each individual molecule changes as it strikes other molecules or the walls. 

According to the Kinetic-Molecular Theory, all gas molecules have the same average kinetic energy (= M2 mu2) at the same temperature, where u is the average velocity. Hence, at the same T ... 

SiH4 is heavier than CH4 however, both molecules have the same average kinetic energy. This is due to the fact that methane molecules have an average speed which is 1.4 times faster than that of silane molecules. 

The average kinetic energy of all the molecules collectively is directly proportional to the absolute temperature of the gas. Equal numbers of molecules of any gas have the same average kinetic energy at the same temperature. 

B. The average kinetic energy of the 02 molecules is greater than that of the He molecules. 

---