Anand posted an Question
July 27, 2020 • 22:12 pm 30 points
  • IIT JAM
  • Chemistry (CY)

(a) isothermal expansion a calculation of ah we know that h e + pv ah a(e + pv) ah ae + a(pv) ah ae = anrt or pv nrt since for an isothermal process, at 0 ae =

in second case, q=-w, w can be nRT and for isothermal process, T=0 , so why q is not zero &it is -w

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    Dinesh khalmaniya 1 best-answer

    because here w = pv = nRT right?? for isothermal process delta T = 0 ( change in temperature) . but in this equation only T is given (not delta T) so i will not zero

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    got it??

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    hi

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    then why in 1st case ∆H= ∆nRT

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    because first case is different here this equation is for delta H. and we know that delta H = deltaE + delta(PV) and second cass is From First law according to this q = delta E - W

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    now got it??

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    Priyanshu kumar best-answer

    For isothermal process T=0 and you know internal energy is a function of temperature so change in internal energy is also 0 ie delta E =0...so q=-W

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    got it anand??

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    any doubt anand??

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    ha

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    yes tell

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    why this is not?

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    we take change in temperature in isothermal process

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    then in 1st case why ∆H= ∆nRT , here T is constant na not change

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    anand in a closed system del n is also equal to zero..and for isothermal process change in temp also equal to zero..so when you go into deeply by considering every thing then concept goes change

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    your only question is this much na anand...why q is not equal to 0??

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    ha

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    some work is done on the system, or by the system. So, for the internal energy to remain the same, as it should on the face of fixed temperature, there has to be some heat moving into or out of the system. Hence, q cannot be zero. when you go mathematically then you have many relations...so you get confused..so conceptually read what happens

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    got anand??

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    ok

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    👍😊

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    anand please mark this answer if your doubt is cleared 😊

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