Final answer:
In a closed-end manometer, the gas pressure is equal to the difference in the height of mercury in the two arms of the U-tube. The gas pressure in this case is -198,720 mmHg.
Step-by-step explanation:
In a closed-end manometer, the gas pressure is equal to the difference in the height of mercury in the two arms of the U-tube. Since the level on the gas side is lower, we can assume that the height difference (h) is negative.
The equation for the gas pressure in a closed-end manometer is:
Pgas = h * rho * g
Given that the difference in the levels of mercury (h) is 150 mm and atmospheric pressure is 795 torr, we need to convert torr to mmHg (1 torr = 1 mmHg). So the atmospheric pressure is 795 mmHg.
Now, we can substitute the values into the equation:
Pgas = -150 mm * (13.6 g/cm3) * (9.8 m/s2) = -198,720 mmHg
The final answer is -198,720 mmHg.
The gas pressure in a closed-end manometer with a mercury level difference of 150mm and an atmospheric pressure of 795 torr is 945 torr, as it is the sum of the atmospheric pressure and the height difference of the mercury.
The subject of this question is gas pressure measurement using a closed-end manometer. When the level on the gas side is lower than the mercury level on the closed side of the manometer, it indicates that the gas pressure is higher than the pressure in the closed side, which is essentially zero. To find the gas pressure, we simply convert the difference in mercury levels to the same units as the atmospheric pressure and add it to the atmospheric pressure if it is given. However, in this case, since the closed-end manometer has essentially a vacuum on the closed side, the gas pressure is directly equal to the difference in mercury levels.
Given:
Height difference in mercury, Δh = 150 mm
Atmospheric pressure, Patm = 795 torr
Since the gas side is lower, the gas pressure, Pgas, is higher than the atmospheric pressure by the height of the mercury column. The gas pressure is calculated as the sum of the atmospheric pressure and the height difference:
Pgas = Patm + Δh
Pgas = 795 torr + 150 mm
Pgas = 945 torr
Therefore, the gas pressure in the system is 945 torr.