A gas sample is connected to a closed-end manometer. The difference in mercury levels in the 2 arms is 115 mm. What is the gas pressure in torr if the atmospheric pressure is 750. torr?
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To determine the gas pressure in torr, we need to consider the difference in mercury levels in the two arms of the manometer. The height difference, known as the "pressure difference," is related to the difference between the gas pressure and the atmospheric pressure.
In this case, the pressure difference is given as 115 mm. We also know that the atmospheric pressure is 750 torr.
To calculate the gas pressure, we can use the formula:
Gas Pressure = Atmospheric Pressure + Pressure Difference
Substituting the given values:
Gas Pressure = 750 torr + 115 mm
However, we need to convert the millimeters (mm) to torr since these units are not the same. 1 mm Hg (mm) is equivalent to 1 torr.
Converting 115 mm to torr:
Gas Pressure = 750 torr + 115 torr
Gas Pressure = 865 torr
Therefore, the gas pressure in torr is 865.
To find the gas pressure in torr, we need to use the difference in mercury levels in the two arms of the closed-end manometer.
In a closed-end manometer, one arm is connected to the gas sample, and the other arm is open to the atmosphere. The pressure of the gas sample can be calculated by measuring the difference in mercury levels between the two arms.
In this case, the difference in mercury levels is given as 115 mm. To convert this measurement to pressure, we need to use the concept of the pressure difference between the gas sample and the atmosphere.
The pressure difference (ΔP) can be calculated using the equation:
ΔP = ρgh
Where:
ΔP is the pressure difference,
ρ is the density of mercury (13,600 kg/m^3),
g is the acceleration due to gravity (9.8 m/s^2),
h is the height difference in meters.
First, we need to convert the height difference from mm to meters. Since 1 meter is equal to 1000 mm, we have:
h = 115 mm / 1000 = 0.115 m
Now we can substitute the values into the equation:
ΔP = (13600 kg/m^3) * (9.8 m/s^2) * (0.115 m) = 17053.6 N/m^2
To convert the pressure from N/m^2 to torr, we need to use the conversion factor:
1 torr = 101325 Pa
So, the gas pressure in torr is:
Pressure (torr) = (17053.6 N/m^2) / (101325 N/m^2/torr)
Simplifying the units, we have:
Pressure (torr) = 0.168 torr
Therefore, the gas pressure in torr is approximately 0.168 torr.