Entropy Changes

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  • Опубликовано: 8 янв 2025

Комментарии • 9

  • @thepirate6521
    @thepirate6521 2 года назад +2

    awesome video, greetings from Poland!

  • @hershyfishman2929
    @hershyfishman2929 2 года назад +1

    1:32 Why does being isothermal mean that dU is 0? Can't potential energy still change even if it's isothermal?

    • @PhysicalChemistry
      @PhysicalChemistry  2 года назад +2

      That is true because we are talking specifically about an ideal gas. For an ideal gas, U = ³/₂ NkT, which was obtained here: ruclips.net/video/sI6I3JZ4tP4/видео.html
      You're certainly correct that things other than temperature can affect the internal energy, for many substances. But for an ideal gas, the only form of energy it has is kinetic energy, so U depends on temperature and nothing else.

  • @shuchenzhou1730
    @shuchenzhou1730 7 месяцев назад

    what would be the enthalpy change if we got a varying pressure?

  • @jorjereyes9491
    @jorjereyes9491 Год назад +1

    What does the horizontal line over the d mean?

    • @PhysicalChemistry
      @PhysicalChemistry  Год назад +2

      That indicates that dq and work are inexact differentials, rather than exact differentials like dU. This is related to the fact that q and w are path functions, while U is a state function.
      Here is the earlier video on inexact differentials: ruclips.net/video/0vkaBwr8OMs/видео.html

  • @mortezakhoshbin
    @mortezakhoshbin 4 года назад +1

    thanks dear Dr.stuart
    I have found a little mistake in the calculations of Flory-Huggins mixing entropy equation that results in a differnt equation that i found it. I need someone to help me varify my developed equation by real datas. It will be honor if you cooperate to make a paper from it. if you are interested please allow me to email you reasons to my claim.thank you

    • @PhysicalChemistry
      @PhysicalChemistry  4 года назад +2

      Flory-Huggins is a great example of the sort of lattice models considered in some of the earlier lectures. (See ruclips.net/video/v7UzSsbHAmw/видео.html) Hopefully I will be able to post a video on the Flory-Huggins polymer model sometime in the future.
      I do have a video posted on the entropy of mixing (see ruclips.net/video/2TbKlXVWAJ4/видео.html), but it is for gases / fluids, and ideal polymer solutions are slightly different.