## Reversible v irreversible

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

Katherine Grillo 1B
Posts: 69
Joined: Fri Sep 28, 2018 12:28 am

### Reversible v irreversible

What does it mean when an expansion is isothermal/reversible? What would be an example of an irreversible expansion?

Becky Belisle 1A
Posts: 81
Joined: Fri Sep 28, 2018 12:18 am

### Re: Reversible v irreversible

If an expansion is isothermal, the change in temperature equals zero. If an expansion is reversible, w= -nRTln(V2/V1). For irreversible expansions, pressure is treated as constant. So, w= -PexΔV.

Posts: 62
Joined: Fri Sep 28, 2018 12:23 am

### Re: Reversible v irreversible

Like the example during class, Prof. Lavelle told us if we were to have a system being held with a lid and the pressure of the system is 2 atm while the surroundings are 1 atm if we were to release the lid, it would shoot upwards. That is an example of an irreversible system.

Saman Andalib 1H
Posts: 73
Joined: Fri Sep 28, 2018 12:16 am

### Re: Reversible v irreversible

It means that temperature is maintained constant and that there is an infinitesimally small pressure difference, resulting in us having to use the integral to solve.

anthony_trieu2L
Posts: 60
Joined: Fri Sep 28, 2018 12:29 am

### Re: Reversible v irreversible

To add, reversible reactions always result in more work because of the infinitesimally pressure differences.