15.13 part a?

Moderators: Chem_Mod, Chem_Admin

Adriana Rangel 1A
Posts: 96
Joined: Fri Sep 29, 2017 7:04 am

15.13 part a?

Postby Adriana Rangel 1A » Sat Mar 03, 2018 4:39 pm

So since the formation of HI is second- order wouldn't the formula for finding the rate = k x concentration^2?
The solutions says " From the units of the rate constant, it follows that the reaction is second-order; therefore, rate= k [H2] [I]

Isita Tripathi 2E
Posts: 52
Joined: Sat Jul 22, 2017 3:00 am
Been upvoted: 1 time

Re: 15.13 part a?

Postby Isita Tripathi 2E » Sat Mar 03, 2018 4:46 pm

They're probably referring to the overall order of the reaction. Since there are two reactants, and each is first order, the overall order = 1+1 = 2.
The rate constant's units depend on the overall order.

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

Re: 15.13 part a?

Postby skalvakota2H » Sun Mar 04, 2018 1:48 am

Note that the equation for the formation of HI is given by: H2 + I2 → 2 HI
Since the question gives that each reactant is to the first order, this means that the total order, given by the sum of individual orders for each reactant, is 1+1, or 2.
A reaction need not be dependent on only one reactant concentration. Two different reactants can be combined in an elementary step, such as this, and still yield a second order reaction, since the reaction order is the total order.

Angel Ni 2K
Posts: 50
Joined: Sat Jul 22, 2017 3:01 am

Re: 15.13 part a?

Postby Angel Ni 2K » Sun Mar 04, 2018 4:25 am

The rate equals k(concentration of H2)(concentration of I2). It is, in a way, k(concentration)^2.

Return to “General Rate Laws”

Who is online

Users browsing this forum: No registered users and 2 guests