Measuring the pressure of a gas

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The pressure difference calculated is 1000 pascals, but there is confusion regarding whether to include atmospheric pressure in the total gas pressure. The book states the gas pressure as 1000 pascals, while the discussion suggests it should be 101,000 pascals when atmospheric pressure is considered. It is noted that when asked for pressure, it typically refers to gauge pressure, which excludes atmospheric pressure, while absolute pressure includes it. The importance of using absolute pressure in gas law calculations is emphasized. Understanding these distinctions is crucial for accurate measurements in gas pressure scenarios.
Steve143
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I worked out that the pressure difference is 1000 pascals

For part b the book says the pressure of the gas is 1000 pascals but shouldn't it be 1000 pascals + 100,000 pascals (atmospheric pressure) making the pressure of the gas 101,000 pascals? because the water has atmospheric pressure on it from the left side of the tube and the gas is not only counteracting it but pushing the water too making me think it is pressure difference + atmospheric pressure. I can't think of a reason why atmospheric pressure would be ignored and it would be stated as 1000
 
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When asked for the pressure it usually means the pressure disregarding atmospheric pressure. If atmospheric pressure is included it is called 'Absolute pressure' of the gas.
When dealing with the gas laws you must use the Absolute pressure.
So you are correct in some applications.
 
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