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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: harps89 on February 07, 2010, 07:10:20 PM

Title: Please help
Post by: harps89 on February 07, 2010, 07:10:20 PM

Consider the conversion of 3 moles of benzene vapour at 40 degrees C and 6kPa pressure to a final state consisting of 1 mole of benzene liquid in equilibrium with 2 moles of benzene vapour at 40 degrees C and 25.3kPa, assuming the vapour behaves ideally.

Given: vapour pressure of benzene at 40 degrees C = 25.3kPa
delta H (vap) = 30.7 kj/mol at 40 degrees C and 25.3 kPa

1. At what pressure does the first drop of liquid appear when the system undergoes a reversible change of pressure at 40 degrees C? Calculate delta H, delta U, w, and q for 3 moles of benzene vapour at 40 degrees C and 6 kPa

2. Calculate delta H, delta U, w and q when 1 mole of benzene is condensed into liquid at 40 degrees C and 25.3kPa

3. What is the total delta H, delta U, q and w for the entire process?

Title: Re: Please help
Post by: Schrödinger on February 08, 2010, 02:31:04 AM

Could you please show us your work?

Title: Re: Please help
Post by: harps89 on February 08, 2010, 08:14:20 AM

I don't know how to start the question