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International Journal of Engineering and Information Systems (ijeais)IJEAIS impact maqolaMaterials and methods
It is difficult to study the motion of an individual molecule in a gas, since as a result of collisions, its speed often changes. At the
same time her mean square speed should be equal to v
sq
. In such In this case, the question arises: what is the proportion of
molecules
having
in
a
given
moment
speed
v
sq
?
In 1859, the English physicist J. Maksvell theoretically found that gas molecules move at different speeds at the same temperature.
According to his theory, the distribution of molecules over speeds has the form of a curve depicted in fig. 10. More molecules are
moving. with a speed of v
m
, which, however, is somewhat less speed v
sq
[
1
].
The velocity of the gas molecules was first experimentally determined in 1920 by the German physicist O. Stern (1888–1969). In
experience, it was found that the speed of silver atoms in vacuum is v
m
= 440 m / s.
Now, theoretically, using formula
𝑉
𝑠𝑞
= √
3𝑅𝑇
𝑀
, we determine the root-mean-square velocity of silver atoms. Knowing that
temperature evaporated silver atoms T = 1233 K (melting point silver), a molar mass M = 0.108 kg / mol, it is possible to
theoretically calculate the mass of a silver atom and the root mean square velocity v
sq
:
𝑣
𝑠𝑞
= √
3∙8,31∙1233
0,108
𝑚 𝑠
⁄ ≈ 5,33 𝑚 𝑠
⁄
This value is slightly higher than the velocity v
m
found in the experiment. According to the Maksvell distribution, the speed v
kv
also a bit more speed v
m
[
2
].
Stern’s experience confirmed the correctness of molecular no-kinetic theory, as well as correct theory
Maksvell on the distribution of molecules according to their
speeds.
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