## Pre Equilibruim Approach

priyasihota3c
Posts: 11
Joined: Fri Sep 25, 2015 3:00 am

### Pre Equilibruim Approach

What is the difference in the pre equilibrium approach and the steady-state approach?

Katherine Jabba 2H
Posts: 15
Joined: Fri Sep 25, 2015 3:00 am

### Re: Pre Equilibruim Approach

The pre-equilibirum approach uses a psuedo-equilibrium situation where one of the steps of the reaction is said to be at equilibrium and set equal to K, the equilibirum constant. This equation involving K is then manipulated and subsituted into the other reaction rate equation, so that the the reaction rate equation of the steps ends up looking like the observed reaction rate. It is a lot simpler method than the steady-state approach, which involves calculus.

Jeremiah Hutauruk
Posts: 67
Joined: Fri Sep 28, 2018 12:28 am

### Re: Pre Equilibruim Approach

involves k

Vicky Lu 1L
Posts: 60
Joined: Fri Sep 28, 2018 12:18 am

### Re: Pre Equilibruim Approach

The pre-equilibrium approach starts with has a fast elementary step followed by a slow elementary step. With the pre-equilibrium approach, we can't have intermediates between the fast and slow in the rate law. This approach also doesn't factor in account the reverse reaction that is occurring in the fast reaction, therefore, we want to substitute a term in for the intermediate step to have an overall rate law that is based on the slow step and does not include in intermediates.

haleyervin7
Posts: 61
Joined: Fri Sep 28, 2018 12:15 am

### Re: Pre Equilibruim Approach

Do you need the observed rate to be given for this approach?

Destiny Diaz 4D
Posts: 51
Joined: Fri Sep 28, 2018 12:28 am

### Re: Pre Equilibruim Approach

would we be specifically asked to solve using the pre equilibrium approach?

Destiny Diaz 4D
Posts: 51
Joined: Fri Sep 28, 2018 12:28 am

### Re: Pre Equilibruim Approach

Destiny Diaz 4D wrote:would we be specifically asked to solve using the pre equilibrium approach?

I feel like based on the question and what is given you would determine this, but I wanted to ask to be sure?