## Reversible vs. Irreversible

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

Dina Geotas 4A
Posts: 61
Joined: Fri Sep 28, 2018 12:29 am

### Reversible vs. Irreversible

I'm still having trouble understanding what reversible means for a reaction? What are the different equations you use for a reversible or irreversible?

Ashley Zhu 1A
Posts: 69
Joined: Fri Sep 28, 2018 12:16 am

### Re: Reversible vs. Irreversible

For a reversible reaction, the system is at equilibrium and when it is either compressed or expanded, it does so slowly in infinitely small increments, and you use the equation w = -nRTln(V2/V1) for work. For an irreversible reaction, the reaction is happening under a constant external pressure Pext, and the work equation is w = -P(deltaV).

Tameen Ahmed 4C
Posts: 30
Joined: Fri Sep 28, 2018 12:19 am

### Re: Reversible vs. Irreversible

For a reversible reaction, delta S of the system is equal to -delta S of the surrounding because delta S universe is equal to zero. For this reaction, you would use w=-nRTln(V2/V1).

For an irreversible reaction, delta S of the universe is equal to delta S of the system because delta S of the surrounding is equal to zero. For this reaction, you would use w=Pexternal*deltaV.

Jessica Chen 1F
Posts: 61
Joined: Fri Sep 28, 2018 12:17 am

### Re: Reversible vs. Irreversible

A reversible reaction would also have more work done and is isothermal (temperature remains constant.)
An irreversible reaction would have less work done and is isobaric (pressure remains constant).

Posts: 64
Joined: Fri Sep 28, 2018 12:26 am

### Re: Reversible vs. Irreversible

For a reversible reaction, you use w=-nRT ln (v2/v1) and for an irreversible reaction, you use w=-Pex times delta V.