# Time to equilibrium

1. Nov 13, 2012

### Miffymycat

Is the time taken to reach equilibrium the same whether starting from reactants or products, under the same conditions? I think intuitively it is but cannot find a reference or proof.

2. Nov 13, 2012

### Simon Bridge

What happens if you switch the roles of the reactants and the products?

3. Nov 14, 2012

### Miffymycat

How do you mean?

4. Nov 14, 2012

### Simon Bridge

I understood you to be talking about an equilibrium reaction ... when the products of a reaction themselves can react ... and, in turn, produce the initial reactants. You can start by mixing the products instead .. in which case they are the initial reactants and the roles have changed.

You should have some model for handling these sorts of reactions ... so have you tried applying the model both ways?
Put another way: I am trying to encourage you to investigate your question yourself instead of looking for some results obtained by someone else.

(But you could be thinking of something else.)

5. Nov 15, 2012

### Miffymycat

Thankyou for the clarification - I see what you meant.

I have thought at quite some length and a colleague of mine is equally at a loss. I am familiar withj the basics of integrated rate laws and the equilibrium law, but just cannot see how to apply this. I have found no reference to this question iun several standard texts, so, short of doing an experiment in the lab (which would only prove it for one case), I am lost! If you have an idea how to prove this, then by all means just give me some clues ... I am happy to wrestle with it once I have a direction to go in!

Many thanks

6. Nov 15, 2012

### Staff: Mentor

Technically time required to reach equilibrium is infinite.

7. Nov 15, 2012

### Simon Bridge

@Borek: Depends on your model :)

@Miffymycat: how would you normally go about figuring the time to equilibrium?