Worksheet: Gas Pressure Measurements
In this worksheet, we will practice describing the mechanisms of common gas pressure gauges and identifying sources of error in pressure measurements.
A manometer is used to measure the pressure of a gas; the gas exerts a force on a column of liquid in the U-tube, causing it to fall at one end and rise at the other. Which of the following properties would make a liquid a bad choice for use in a manometer?
- AHigh density
- BLow toxicity
- CHigh thermal expansion
- DLow reactivity
- ELow vapor pressure
How would the use of a volatile liquid affect the measurement of a gas using open-end manometers versus closed-end manometers?
- AIt will not affect the closed-end manometer readings but will increase the readings for the open-end manometer.
- BIt will not affect the open-end manometer readings but will increase the readings for the closed-end manometer.
- CIt will introduce a systematic error in both cases.
- DIt would have no effect in either case.
The pressure of a sample of gas is measured at sea level with an open-end mercury manometer. Assuming atmospheric pressure is 760 mmHg, what is the pressure of the gas?