Isothermal and reversible expansion work problem (Physical Chem)

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SUMMARY

The discussion focuses on calculating the work (w) and heat (q) for the isothermal and reversible condensation of 2.00 moles of methanol (CH3OH) at 64°C. The standard enthalpy of condensation is given as -35.3 kJ/mol. Participants highlight the challenge of determining the initial and final volumes (Vi and Vf) necessary for the work calculation using the formula w = -nRT * ln(Vf/Vi). Suggestions include using the ideal gas law for volume estimation and considering the Van der Waals equation for real gas behavior.

PREREQUISITES
  • Understanding of isothermal processes in thermodynamics
  • Familiarity with the ideal gas law and its applications
  • Knowledge of enthalpy and its significance in phase changes
  • Basic skills in manipulating logarithmic equations
NEXT STEPS
  • Learn to apply the ideal gas law to calculate the volume of gases at specific conditions
  • Study the Van der Waals equation for real gas behavior and its implications
  • Explore the concept of enthalpy changes during phase transitions in detail
  • Investigate the relationship between density, mass, and volume for liquids and gases
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Chemistry students, physical chemists, and anyone studying thermodynamic processes related to phase changes and gas behavior.

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Homework Statement


A sample of 2.00 mol. CH3OH (g) is condensed isothermally and reversibly to liquid at 64*C. The standard enthalpy of condensation of methanol @ 64*C is -35.3 kJ/mol. Find w and q for the reaction.


Homework Equations


w = -nRT * ln(Vf/Vi) (although I don't have volume so I don't know how to find it)


The Attempt at a Solution



Honestly I can't find any other reversible/isothermal condition work formulas to use. I am sure I am just missing how to calculate volume here. I have n, R, and T but am not given V. Not sure if this can be calculated?
 
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What is the volume of 2 mol of methanol at 64C? Make an assumption about it's density and calculate it (I assume you know how to convert moles to mass). Same thing goes for the volume of 2 moles of gas (methanol before condensation). The ideal gas equation might not be completely accurate but it is a good place to start.
 
Well, I am stuck on the same problem. I don't think that the ideal gas expression is the correct one... also, what do you get if you do 64 kJ/mol * 2 mol ? (I think this is the enthalpy for the reaction). And then, should you go back to the Van der waals equation for the real gas and implement that in your calculation of work ?
 

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