## reversible expansion

$w=-P\Delta V$
and
$w=-\int_{V_{1}}^{V_{2}}PdV=-nRTln\frac{V_{2}}{V_{1}}$

nshahwan 1L
Posts: 100
Joined: Fri Aug 30, 2019 12:18 am

### reversible expansion

Could someone explain how the small change is made to reverse a process? Like I understand a very small part of a variable is changed (like pressure) but how would that be done?

Niharika 1H
Posts: 50
Joined: Thu Jul 25, 2019 12:16 am

### Re: reversible expansion

A process is reversible if an extremely small change can reverse it. For example, an extremely small increase in pressure can move an object into a container, while an extremely small decrease in pressure can push the object out. No change in pressure won't move the object.

Petrina Kan 2I
Posts: 102
Joined: Fri Aug 30, 2019 12:17 am

### Re: reversible expansion

This small change in parameter or pressure can be done using a piston.

005162520
Posts: 101
Joined: Tue Sep 24, 2019 12:17 am

### Re: reversible expansion

How can we calculate a reversible expansion?

Natalie Benitez 1E
Posts: 100
Joined: Fri Aug 02, 2019 12:15 am

### Re: reversible expansion

How would we know on the exam if something is reversible or irreversible ?

nshahwan 1L
Posts: 100
Joined: Fri Aug 30, 2019 12:18 am

### Re: reversible expansion

Thanks for the replies. Also I think they will tell us if it is reversible but I am not sure. For example if it is isothermic should we assume it to be reversible?

Nare Nazaryan 1F
Posts: 101
Joined: Fri Aug 09, 2019 12:17 am

### Re: reversible expansion

Natalie Benitez 1E wrote:How would we know on the exam if something is reversible or irreversible ?

I believe it is reversible if the pressure is not constant and if the internal and external pressure are the same.