Wednesday, May 18, 2011

Isothermal Reversible Expansion Work of an IDEAL Gas

Consider an ideal gas confined in a cylinder with a frictionless piston. The reversible
expansion of gas takes place in a finite number of infinitesimally small
intermediate steps. If the Pext is infinitesimally less than internal
pressure of gas ‘P’ by ‘dP’. Then gas expands reversibly and piston moves
through a distance ‘dl’.              
Since dP is so small, for all practical purposes.                              
Pext.  – Pgas  = P.              
One work done by gas in one infinitesimal step (dw) can be expressed as;                              
dw   =   P  ´  dV.         [ w = P ´ DV]                        
\dw  =   PdV.                            
If the gas expands from V1 to V2 during isothermal
reversible expansion. The total amount of work done would be equal to

5 comments:

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  2. What if no of moles remains same

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  3. what will be the enthalpy change

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  4. what will be the enthalpy change

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