Estimate Mass H2O Vapor in 1 m^3 Air at +20°C

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To estimate the mass of water vapor in 1 m³ of saturated air at 20°C, the saturation pressure for water vapor at this temperature is essential. The ideal gas law can be applied using the formula m_{H2O} = P_{sat, H2O} / (R_{H2O}T), but attention to units is crucial for accuracy. The discussion highlights a potential issue with the phrasing of the problem, suggesting it may not be physically correct. Clarification on the problem's wording is necessary to ensure proper understanding and application of the concepts. Accurate calculations depend on both the correct use of the ideal gas law and the precise definition of saturation in this context.
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Homework Statement


Estimate the mass of water vapor that is contained in 1 m^3 of saturated air at a temperature of plus 20 degrees Celsius

2. The attempt at a solution
I looked up the saturation pressure for water vapor at the given temperature. Can I just use the ideal gas-law for the mass? i.e. is the solution as simple as
m_{H_2O} = \frac{P_{sat, H_2O}}{R_{H_2O}T}
or do I have to make another approach?
 
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yes this looks right, but -as usual- be careful with the units
 
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Can you tell me why the phrasing of the problem is physically incorrect?
 

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