Rate limiting step

$aR \to bP, Rate = -\frac{1}{a} \frac{d[R]}{dt} = \frac{1}{b}\frac{d[P]}{dt}$

Deena Doan 2F
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Joined: Sat Aug 17, 2019 12:17 am

Rate limiting step

What is the rate-limiting step?

jisulee1C
Posts: 149
Joined: Thu Jul 25, 2019 12:17 am

Re: Rate limiting step

the rate limiting step is the slowest step

Amanda Lin 2I
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Joined: Sat Aug 17, 2019 12:15 am

Re: Rate limiting step

The rate limiting step is the slowest step, and it determines the rate of the overall reaction.

Eunice Nguyen 4I
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Joined: Sat Aug 17, 2019 12:17 am

Re: Rate limiting step

The rate-limiting step is the slowest step of the reaction. You'll be using the rate law of the rate-limiting step as the overall rate.

Martina
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Joined: Thu Jul 25, 2019 12:16 am

Re: Rate limiting step

It is the slowest step of the reaction, since the other steps are much faster, it determines the rate of the overall reaction.

Dina 2k
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Re: Rate limiting step

how would u determine which elementary step is the limiting?

Sarah Zhari 1D
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Re: Rate limiting step

Dina 2k wrote:how would u determine which elementary step is the limiting?

I think that most likely, they would tell us which one is the slow step. At least that's what the problems in the textbook do.

Sean Cheah 1E
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Joined: Wed Sep 18, 2019 12:20 am

Re: Rate limiting step

If you are given a reaction mechanism and an overall rate law, sometimes it is possible to intuitively determine the slow step. This is because the overall reaction rate is determined by the rate of the slow step (which is why it is also called the rate-limiting step). For example, the reaction NO2 + CO --> NO + CO2 follows rate = k[NO2]^2. If the elementary steps are 2NO2 --> NO + NO3 and NO3 + CO --> NO2 + CO2, the former is the slow step because it is the one that has the collision of two NO2 molecules as you would expect given the exponent of 2 on [NO2] in the overall rate law.

Samuel Tzeng 1B
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Joined: Sat Aug 24, 2019 12:15 am

Re: Rate limiting step

it's the slowest step in a reaction

Anna Heckler 2C
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Re: Rate limiting step

The slowest step in the reaction determines the overall rate law.

Julia Holsinger_1A
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Joined: Tue Feb 26, 2019 12:16 am

Re: Rate limiting step

It is the slowest step in the reaction

Julia Holsinger_1A
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Joined: Tue Feb 26, 2019 12:16 am

Re: Rate limiting step

How do you find the limiting step?

Daniela Shatzki 2E
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Joined: Sat Aug 24, 2019 12:16 am

Re: Rate limiting step

the slowest step of the reaction is the rate-determining step

Tanmay Singhal 1H
Posts: 143
Joined: Sat Jul 20, 2019 12:16 am

Re: Rate limiting step

the slowest step that determines the rate of the reaction. cataylst in another step doesnt change rate of overall reaction