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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: 21385 on June 23, 2008, 02:04:59 PM

Title: Rate Kinetics
Post by: 21385 on June 23, 2008, 02:04:59 PM

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Question: Assuming the steady state of O (d[ O ]/dt=0), derive the rate equation.

Here's the answer: (https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fi28.tinypic.com%2Fwi3i1x.jpg&hash=fe253f565c4e00dff701d13ff83733b40e2ecb9b)\


Can someone explain to me why it is 2k2[O3][ O ], rather than just k2[O3][ O ], without the 2?

Thanks a lot

Title: Re: Rate Kinetics
Post by: tamim83 on June 23, 2008, 04:00:01 PM

The 2 is coming from the overall reaction that you are given.  The rate of O₃ disappearing is (1/2) (dO₃/dt)), which is equal to k₂[O3]

• .  You then multiply each side by 2 to get rid of the 1/2. 

Title: Re: Rate Kinetics
Post by: 21385 on June 29, 2008, 12:10:06 PM

Perfect, thank you very much