Hydrogen molecule average speed

At what temperature will a molecule of uranium hexafluoride, the densest gas known, have the same average speed as a molecule of the lightest gas, hydrogen, at 37°C ... 

FIGURE 4.26 The average speeds of gas molecules at 25°C in meters per second. The gases are some of the components of air hydrogen is included to show that the average speed of light molecules is much greater than that of heavy molecules. 

Hydrogen is a colorless, odorless, tasteless gas (Table 14.1). Because H2 molecules are nonpolar, they can attract each other only by London forces. Each molecule has only two electrons, and hence only a very small instantaneous electric dipole therefore these forces are so weak that hydrogen does not condense to a liquid until it is cooled to 20 K. Because of these weak inter molecular forces, it has only low solubility in many liquids, particularly polar liquids. Furthermore, H2 molecules are so small and move at such a high average speed that molecules of hydrogen gas diffuse more rapidly than those of any other substance. 

Thus it is possible to compute the average speed of gas molecules merely from a knowledge of the pressure p and gas density p. For hydrogen under standard conditions, C = 1696 m/s, approximately the speed of a bullet. This simple derivation is reasonably accurate, even though the assumption is made that all molecules are traveling at the same velocity. Often simplifying assumptions permit the parameters in an equation to be identified, even if the values of the constants may be somewhat inaccurate. 

The average speed of a molecule in a given gas depends only on the temperature. At normal temperature and for gases of molecular mass 30 g mol 1 this is of the order of 500 m s 1. Light hydrogen molecules move with an average speed of 2000 m s 1 at the... 

Compute the root-mean-square speed, the average speed, and the most probable speed of an oxygen molecule at 300 K and at 500 K. Compare with the values for hydrogen. 

In a binary collision between hard-sphere molecules, what ratio of molecular masses results in the maximim transfer of translational energy What is AE /EjO for collision between hydrogen (A) and oxygen (B), each with a line-of-center velocity equal to one-half the average speed at 25°C (given in Table 2.2b) ... 

EXERCISE 5.13 At what temperature do hydrogen molecules, H2, have the same rms speed as nitrogen molecules, N2, at 455°C At what temperature do hydrogen molecules have the same average kinetic energy ... 

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