Question 51 in the homework  [ENDORSED]


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104422816
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Question 51 in the homework

Postby 104422816 » Mon Feb 15, 2016 10:36 pm

15.51 The following mechanism has been proposed for the reaction between nitric oxide and bromine:
Step 1: NO -> Br2 + NOBr2 (slow)
Step 2: NOBr2 + NO + NOBr -> NOBr (fast)
Write the rate law for the formation of NOBr implied by this mechanism.

The explanation for the answer: k(NO)(Br2) says that this is a second order reaction but i thought second order equation is (a)^2

Reine Nakamura 1C
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Re: Question 51 in the homework

Postby Reine Nakamura 1C » Tue Feb 16, 2016 12:48 am

It's a second order reaction because the overall order of the reaction is the sum of the orders for [NO] and [Br2]. In this case both are first order, making the overall order 2.

Jade Fosburgh Discussion 2C
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Re: Question 51 in the homework  [ENDORSED]

Postby Jade Fosburgh Discussion 2C » Sat Feb 24, 2018 10:25 pm

Why is the speed of the rxn relevant in this problem? (slow vs fast)

Chem_Mod
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Re: Question 51 in the homework

Postby Chem_Mod » Mon Feb 26, 2018 2:17 pm

This is to show that the first step is the most important overall for determining reaction rate, as it is slower than the second, making it rate-limiting.

Dang Lam
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Re: Question 51 in the homework

Postby Dang Lam » Wed Feb 28, 2018 10:01 pm

Chem_Mod wrote:This is to show that the first step is the most important overall for determining reaction rate, as it is slower than the second, making it rate-limiting.

so which reaction (slow or fast) should we use to write our rate law?


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