Can Air Be Treated as an Ideal Gas in Absolute Zero Calculations?

AI Thread Summary
The discussion centers on the calculation of absolute zero in a lab experiment, where the accepted value is -273°C, while the calculated value was -72.18°C. Participants confirm that air can be treated as an ideal gas for calculations near room temperature and even down to -100°C, suggesting the discrepancy indicates an error in the calculations. It is emphasized that a reasonable experimental value should be within 50 degrees of the accepted temperature. The conclusion is that the significant difference in values likely points to a mistake in the experimental approach or calculations.
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Homework Statement


Calculate your experimental value of absolute zero , how does your experimental value compare to the theoretical value -273C?


Homework Equations


T_abs=(S1*T2-S2*T1)/(S1-S2)


The Attempt at a Solution



This is all part of a lab. I'm not asking people to do any calculations. I'm more worried about my calculations from what I got and I'm pretty sure I did them correctly. The accepted value for absolute zero is -273C. The value I got when calculating was -72.18 C. My question is can air be treated as an ideal gas so that the calculation on absolute zero is possible? If air can't be treated as an ideal gas then it would explain the huge difference in my value vs the accepted value.

Thanks!
 
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The ideal gas approximation is VERY good for air near room temperature. I'd say it's extremely accurate up to at least -100 degrees Celsius.
 
ideasrule said:
The ideal gas approximation is VERY good for air near room temperature. I'd say it's extremely accurate up to at least -100 degrees Celsius.

So that means I did something wrong right?
 
Yes, I'd say so. You should be able to get a reasonable value (within 50 degrees or so of the actual answer).
 
ideasrule said:
Yes, I'd say so. You should be able to get a reasonable value (within 50 degrees or so of the actual answer).

ok. thanks for letting me know
 
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