## Irreversible and Reversible Processes

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

Joanne Guan 1B
Posts: 30
Joined: Sat Jul 22, 2017 3:01 am

### Irreversible and Reversible Processes

I understand that a reversible process is one that can be reversed by an infinitely small change and an irreversible process is expansion against an external pressure that differs by a finite amount from the system's pressure. Can someone give examples for these two processes?

Alexia Joseph 2B
Posts: 56
Joined: Thu Jul 27, 2017 3:01 am

### Re: Irreversible and Reversible Processes

In class, the example Dr. Lavelle used was with two systems compressed with pistons.

Irreversible expansion: will have sudden expansion (results in a large change in volume)
Pressure of external atmosphere- 1 atm
Pressure of system- 2 atm

Reversible expansion: system will change slowly (results a very small change in V)
Pressure of external atmosphere- 1 atm
Pressure of system- 1 atm

804899546
Posts: 51
Joined: Sat Jul 22, 2017 3:00 am

### Re: Irreversible and Reversible Processes

So if the difference is that reversible reactions occur at equilibrium, what makes a reaction that occurs at non-equilibrium irreversible?

Kevin Tabibian 1A
Posts: 42
Joined: Fri Sep 29, 2017 7:06 am

### Re: Irreversible and Reversible Processes

An irreversible process would be as if I took a single 10g weight off of a balloon, allowing it to quickly expand. While a reversible process would be as if I individually removed from a balloon infinitely small weights that all collectively added up to 10g. The work in the second case would be much larger.

504754253
Posts: 45
Joined: Fri Jun 23, 2017 11:39 am

### Re: Irreversible and Reversible Processes

can someone explain what makes a reaction that occurs at non-equilibrium irreversible? and give an example