## Isothermal irreversible reactions

isochoric/isometric: $\Delta V = 0$
isothermal: $\Delta T = 0$
isobaric: $\Delta P = 0$

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Anisha Chandra 1K
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Joined: Thu Jul 11, 2019 12:17 am

### Isothermal irreversible reactions

Is the delta U of an isothermal irreversible reaction also equal to 0, like it is for an isothermal reversible reaction? If it's not equal to 0, why is that?

Benjamin Feng 1B
Posts: 102
Joined: Sat Sep 07, 2019 12:19 am

### Re: Isothermal irreversible reactions

Because internal energy is a state function, that means that it will be the same regardless of the path taken. If the initial and final temperature are the same, then U = 0.

Emma Popescu 1L
Posts: 105
Joined: Wed Sep 11, 2019 12:16 am

### Re: Isothermal irreversible reactions

The internal energy is dependent on temperature and an isothermal reaction takes place at constant temperature. Thus, in any isothermal process involving only ideal gases, delta U=0. This is because the energy gained as heat (q) is equal to the amount of work done by the system (q = -w).

Helen Struble 2F
Posts: 97
Joined: Sat Aug 24, 2019 12:17 am

### Re: Isothermal irreversible reactions

Anisha Chandra 1K wrote:Is the delta U of an isothermal irreversible reaction also equal to 0, like it is for an isothermal reversible reaction? If it's not equal to 0, why is that?

I'm having trouble wrapping my head around an isothermal irreversible expansion. In isothermal reversible expansions, all the energy transferred to the surroundings by the work of expansion is immediately replace by heat flowing in from the surroundings to the system, keeping the temperature between surroundings and system any equilibrium. In order for this to happen, the expansion must happen slowly and reversibly. How would an isothermal irreversible expansion take place?

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