During the time 0.332 mol of an ideal gas undergoes an isothermal compression at 26.4 C, 383 J of work is done on it by the surroundings. The final pressure is 1.87 atm. What was the intial pressure?

Respuesta :

Answer:

[tex]P_{i}[/tex] = 2.97 atm

Explanation:

The work in thermodynamic processes has several expressions, in the case of isothermal processes the work is

      W = n RT ln ( [tex]V_{i}[/tex] /  [tex]V_{f}[/tex])

Where R is the constant of the ideal gases with a value of 8.314 J / mol K and T the absolute temperature

Let's look for the volume ratio

    T = 26.4 +273.15 = 299.55k

    Ln ( [tex]V_{i}[/tex] /  [tex]V_{f}[/tex])

= W / n RT

    Ln( [tex]V_{i}[/tex] /  [tex]V_{f}[/tex])

= 383 / (0.332 8.314 299.55)

    Ln( [tex]V_{i}[/tex] /  [tex]V_{f}[/tex])

= 0.4632

     ( [tex]V_{i}[/tex] /  [tex]V_{f}[/tex])  = e 0.4632

    ( [tex]V_{i}[/tex] /  [tex]V_{f}[/tex])  = 1,589

Let's use the ideal gas equation for two volumes

   [tex]P_{i} V_{i}[/tex]  = n R T

  [tex]P_{i} V_{i}[/tex]   = n RT

The temperature is the same because it is an isothermal process, this equation is the same

   [tex]P_{i} V_{i}[/tex]   = [tex]P_{f} V_{f}[/tex]

   Vi / Vf = [tex]P_{f}/P_{i}[/tex]  

  [tex]P_{i}[/tex]=  [tex]P_{f}[/tex]  [tex]V_{i}[/tex] /  [tex]V_{f}[/tex]

   [tex]P_{i}[/tex] = 1.87 1,589

   [tex]P_{i}[/tex] = 2.97 atm