Change Of Pressure Lab Report
Discussion The overall purpose of the experiment is to observe the change of pressure as three different gases; N2, He, and an unknown gas effuses through a pinhole into a vacuum environment. Each gas has a different pattern of changing the pressure depending on its molecular mass, which is related to the kinetic theory of gases, where heavier gases (N2) effuse slower than lighter gases (He). The experiment setup was prepared, measurement of change of pressure as a function of time were recorded. After performing two trials of each of N2, He, and the unknown gas, the collected data were then analyzed and plotted as a graph of double Y-axis of Pressure (microns) and ln(P/P0), and an X-axis as a change in time (s), the exponential decay was observed in the plotted graphs. Each graph was then analyzed by doing a linear fitting of
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No, a three-fold increase in temperature will not cause a three-fold in speed. As observed from the graphs at 100 K and 300 K, the speed was doubled when the temperature increased from 100 K to 300 K.
• How do the plots change when the molecule changes? What trend is observed? Look carefully at the speed axis (the x-axis).
Changing the molecule, changed the plot. Heavier molecules I2 had a lower speed distribution than lighter molecules H2. The trend is lighter molecules move faster, thus it will have a larger distribution range. While heavier molecules move slower and have a smaller distribution range.
Because gas molecules move randomly at different speeds in all directions, and the fact that the velocity is a vector, opposite directions will cancel each other. Gas moving to the right has positive velocity direction cancels out the gas moving to the right that have a negative velocity direction. Thus, if those cases have the exact same speed, but are moving in the exact opposite direction given an average velocity of zero m/s.
No, a three-fold increase in temperature will not cause a three-fold in speed. As observed from the graphs at 100 K and 300 K, the speed was doubled when the temperature increased from 100 K to 300 K.
• How do the plots change when the molecule changes? What trend is observed? Look carefully at the speed axis (the x-axis).
Changing the molecule, changed the plot. Heavier molecules I2 had a lower speed distribution than lighter molecules H2. The trend is lighter molecules move faster, thus it will have a larger distribution range. While heavier molecules move slower and have a smaller distribution range.
Because gas molecules move randomly at different speeds in all directions, and the fact that the velocity is a vector, opposite directions will cancel each other. Gas moving to the right has positive velocity direction cancels out the gas moving to the right that have a negative velocity direction. Thus, if those cases have the exact same speed, but are moving in the exact opposite direction given an average velocity of zero m/s.