Negative Order

Moderators: Chem_Mod, Chem_Admin

Hellen Truong 2J
Posts: 50
Joined: Sat Jul 22, 2017 3:00 am
Been upvoted: 1 time

Negative Order

Postby Hellen Truong 2J » Fri Mar 09, 2018 8:49 am

After you determine what order the reaction is with respect to each reactant, what does it mean conceptually when you get a negative order?

Hazem Nasef 1I
Posts: 51
Joined: Tue Oct 10, 2017 7:13 am

Re: Negative Order

Postby Hazem Nasef 1I » Fri Mar 09, 2018 10:20 am

A negative order means that as the concentration of that substance is increased, the rate of the reaction decreases. An example of this would be a product with a negative order. If the concentration of this product is increased, it participates in a reverse reaction, thereby slowing down the reaction rate.

skalvakota2H
Posts: 52
Joined: Sat Jul 22, 2017 3:01 am

Re: Negative Order

Postby skalvakota2H » Fri Mar 09, 2018 12:21 pm

A negative order means that the concentration of a species inversely affects the rate of a reaction.

Jenny Cheng 2K
Posts: 30
Joined: Fri Sep 29, 2017 7:05 am
Been upvoted: 1 time

Re: Negative Order

Postby Jenny Cheng 2K » Fri Mar 09, 2018 10:29 pm

A negative order means the concentration appears in the denominator of the rate law. Increasing the concentration of the species (usually a product) slows down the reaction.

Jasmin Tran 1J
Posts: 54
Joined: Thu Jul 27, 2017 3:00 am

Re: Negative Order

Postby Jasmin Tran 1J » Fri Mar 09, 2018 11:32 pm

A reaction rate can have a negative partial order with respect to a substance. For example, the conversion of ozone (O3) to oxygen follows the rate equation (rate = k[O3]^2/[O2]) in an excess of oxygen. This corresponds to second order in ozone and order (-1) with respect to oxygen. When a partial order is negative, the overall order is usually considered as undefined, so in above example, the reaction is not described as first order even though the sum of the partial orders is 2 + (-1) = 1, because the rate equation is more complicated than that of a first-order reaction.

Brandon Fujii 1K
Posts: 51
Joined: Fri Sep 29, 2017 7:04 am

Re: Negative Order

Postby Brandon Fujii 1K » Sat Mar 10, 2018 5:33 pm

A negative first order would occur if a the rate is halved when the concentration of a reactant is doubled.

diangelosoriano
Posts: 49
Joined: Fri Sep 29, 2017 7:07 am

Re: Negative Order

Postby diangelosoriano » Sun Mar 11, 2018 5:53 pm

Are there ever occurrences of negative orders less than -1? Will these be possible / conceptually what would that mean in relation to rates / changing concentration?

Sophia Bozone 2G
Posts: 51
Joined: Fri Sep 29, 2017 7:07 am

Re: Negative Order

Postby Sophia Bozone 2G » Sun Mar 11, 2018 5:56 pm

Conceptually, a reaction with a negative order means that as you increase the concentration of reactant, the reaction rate actually decreases. This seems to eb an interesting phenomena to me, and I 'm sent sure of any real life examples of it.


Return to “Method of Initial Rates (To Determine n and k)”

Who is online

Users browsing this forum: No registered users and 1 guest