### Reversible and Irreversible entropy equations

Posted:

**Mon Jan 30, 2017 6:39 pm**I'm confused on which equations to use for the reversible and irreversible entropy problems. The equation Delta(S) = NR(lnV2/V1) is reversible, but can this still be used to solve an irreversible problem assuming that the change in entropy is not 0? So if you were to use this equation for an irreversible problem you could assume there is no reversible reaction that is the opposite sign and causes change in entropy to be 0. Does this apply for any reversible equation you can use for work or entropy?