How can we determine if a reaction is reversible or not?

[Calle]

how can we determine if a reaction is reversible or not?

Zn2+ (aq) + 2e- -> Zn(s)
is this a reversible reaction?

thanks!

 

[chemisttree]

That's not even a reaction... it's only a half reaction! Where did the electrons come from? The entire reaction must be shown to answer the question.

 

[Calle]

oops.. this is the full reaction, it's the zinc-copper cell redox reaction.

Cu2+(aq) + Zn(s) -> Cu(s) + Zn2+(aq)

 

[Vagrant]

Aren't redox reactions always irreversible?

 

[chemisttree]

They can be reversible if a reverse potential is applied as in rechargeable batteries. As shown, it is not reversible.