pseudo vs 2nd order


Moderators: Chem_Mod, Chem_Admin

Vanessa Reyes_1K
Posts: 60
Joined: Fri Sep 28, 2018 12:28 am

pseudo vs 2nd order

Postby Vanessa Reyes_1K » Sun Mar 10, 2019 11:02 pm

When is it appropriate to use the pseudo 1st order for a reaction?

Amy Lefley 1J
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

Re: pseudo vs 2nd order

Postby Amy Lefley 1J » Sun Mar 10, 2019 11:08 pm

It is appropriate to use pseudo-first order rate law when all reactant concentrations are changing, making the reaction very difficult to study. In this case, we make one reactant concentration small and the others large so that the reaction rate is dependent on only one reactant.

Linh Vo 2J
Posts: 61
Joined: Sat Apr 28, 2018 3:00 am

Re: pseudo vs 2nd order

Postby Linh Vo 2J » Sun Mar 10, 2019 11:08 pm

To add, in discussion, my TA told me it's appropriate to use it when n=1.

Dimitri Speron 1C
Posts: 60
Joined: Fri Sep 28, 2018 12:17 am
Been upvoted: 1 time

Re: pseudo vs 2nd order

Postby Dimitri Speron 1C » Mon Mar 11, 2019 10:06 pm

You can use the pseudo especially when your rate law is dependent on multiple reactants. If the reaction is first order with respect to any of them it can be rewritten as pseudo-first order.

Sophia Ding 1B
Posts: 62
Joined: Fri Sep 28, 2018 12:16 am

Re: pseudo vs 2nd order

Postby Sophia Ding 1B » Wed Mar 13, 2019 3:25 pm

Is it safe to assume that we'll always be told which reactants will be in large excess to us to be able to write the pseudo rate law?


Return to “First Order Reactions”

Who is online

Users browsing this forum: No registered users and 1 guest