Rate Law for a Mechanism with a Fast Initial Step

How to determine the rate law for a mechanism with a fast initial step. Remember, the overall rate law must be determined by experiment. Therefore, the rate law must contain no reaction intermediates.

[@lawl3zz]

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[@BensChemVideos]

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So, I just watched all the videos in your "Chemical Kinetics" playlist........Thank You! I understand this stuff waaaay more now! Thank you!!!!!!!!!

[@marisolbojalil7815]

Explained way better than my chem prof... have an exam in 2 days!!! thank you so much!!!!

[@yessirrr4326]

Explained it waay better than my AP chem teacher...Thanks!

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[@fuegopunchlines1165]

Watched the entire chem kinetics playlist... understand it now great job and thanks

[@ashanpdw]

Even after 6 years, this is helpful. Thank you :)

[@BensChemVideos]

@vegassDJ I just watched it. Although I generally don't like hearing the sound of my own voice, it sounds particularly awful here. I think i may have been sick that day. Thanks for the suggestion!

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[@christinarivera1610]

very helpful, thank you!!!

[@BensChemVideos]

You're very welcome! Many thanks for watching and commenting 😀

[@gaberhunter]

Thank you so much! You teach better than my AP Chem. teacher!

[@alejandradiazruiz16]

This was so helpful! Thank you so much for your help. I love the step by step explanation. I can't thank you enough!! :D

[@angelaviducich2655]

Thank you so much! This was incredibly helpful

[@nuhanuha5206]

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[@BonnieRowland]

Great video! Very helpful and explained the concepts well. Thank you!

[@biscuitmeowed]

I'm glad I watched this before my university chem 2 final otherwise I don't think I would have ever learned it as well.

[@luffymmh]

this video helped me a lot. thanks

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BLESS YOUR SOUL. SAVED MY LIFE

[@syarahfatiha03]

It really helps to clear things out😍

[@BensChemVideos]

@@syarahfatiha03 awesome, glad to hear that 😀

[@darmoore8966]

That was very helpful! I wish my teacher had said this.

[@mattmcguire5350]

You are a genius bro. Keep up the good work

[@dance31115]

thank you so much! i have a final coming up and this was so helpful

[@potatoman6770]

Is this the pre-equilibrium method?

[@pmvillers]

An amazing explanation, thank you.

[@BensChemVideos]

You're very welcome! 😃

[@shyannvaskevicius8621]

Thanks for helping me lessen my chances of failing my Chem 115 midterm tomorrow

[@jamesdurham3279]

thanks for the video and help! this video was very clear and went step by step!

[@DyingWillofTheUchiha]

This helped a lot. Thank you very much.

[@BensChemVideos]

You're very welcome! Many thanks for watching and commenting 😀

[@bennelson2789]

Dude this is amazing thank you so much brother!

[@BensChemVideos]

You're very welcome! Thanks for your kind words 😀

[@mohammednassar4148]

thank you so much it was so confusing but it's clear now to me

[@_colourway]

I'm really grateful for the help. Thank you!

[@singoyl]

this is called the steady-state approximation, right? thank you so much for your videos!! keep them going because they really help me. you teach way better than my professors :)

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[@adansilva6851]

Wait why isn’t the [H2] squared in the final rate equation if the H2 in the overall equation has a 2 coefficient?

[@potatoman6770]

That only applies to ELEMENTARY reactions (reactions with only one step). If you have a multi-step reaction, it is a different story.

[@Didelmaful]

Are the steps always given? If not, how can you determine by yourself when the step is fast or slow? Thank you.

[@sabaal-yafie5529]

Thank you alot :) It really helped me, I have asked a question but there is no one could answer me clealy which is " Whats does K rate constant exactly represent??" I hope Yours or any one answer me. And thank you in advance .

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Thank you very much...very usefull videos !

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[@BensChemVideos]

You're very welcome!

[@Hasko-j9t]

thank you so much. you are awesome teacher.

[@xXsoulcatcher]

Hi ! Your video really helped a lot (:
However I was hoping you could clarify a question I have - why is it that for the intermediate steps , the powers of the reactants are the same as the coefficients, but when we are looking at the overall balanced equation the powers for the initial reactants are not necessarily the same as the coefficients . I hope my question doesn't confuse you ! ): sorry and thanks a bunch (:

[@eriknelson2559]

Must a fast first elementary reaction be an equilibrium one? Could you have a full forward arrow on the first fast rxn?

[@bombasticbrian.]

That was beautifully done. Thank you

[@zhenccc]

thank you! amazing!

[@ilovemyprs]

That helped me SO much omg!
Thanks alot!!!

[@roshanshaji5170]

Thanks a lot!!!! Really helpful

[@dotway]

So helpful!! Thanks so much!

[@jugglingmaster647]

So helpful thank you

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That was a great help, thx!

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So helpful, thank you so much!

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that was an amazing vid dude. thanks

[@muhammadericali]

REALLY helpful! Thanks a lot, brother. Best wishes and God bless :)

[@forevalynn]

hi! why is it that k-3 is usually ignored?

[@tev.8525]

Love you man

[@jferro96]

Wow, great video dude.

[@mattcousins6456]

great video, thanks

[@Mrwowhobbs]

thank u very much helped a ton

[@codys2640]

shouldn't the observes rate law be k [H2]^2 [NO]^2 ? If so, the derived rate law of
k_2 [H2] [NO]^2 isn't consistent because the ^2 is absent from the [H] concentration

[@megafan2453]

Thank. You. Very. Much.

[@HeavenWolfGaming]

10 billion % helpful

[@BensChemVideos]

Very cool!

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Thank you so much for this!

[@juicyballsok]

excellant video thank you!
-Khalissi

[@johngattone3515]

Very helpful

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Reviewing for my AP chem test lol thank you so much

[@MaddieSilverstone]

This was amazing.

[@gator746]

Life-saver!!!!!!!!!

[@daynasaur11]

THANK YOU SO MUCH

[@jhmasoud]

Thank you very much for explaining this. It was the exact example from the ebbing book and was having issues with it. They really can't explain shit in that book. I think they try to make it seem complex for job security... this is just high school algebra with elements, at best.
Cheers.

[@geniusgene]

Thank you so much!

[@heidiblack01]

i have a mechanism that is Cl2(g) (equilibrium arrows) 2Cl(g) (and other steps) I need Cl by itself as the intermediate for another step... i end up with k1/k-1[Cl2]=[Cl]^2 .... How can I get Cl by itself to put it into rate2=k3[Cl][CHCl] where Cl is the intermediate in the equation

[@HazulMin]

can you explain more in detail why the [NO] is squared?

[@aayushlamsal7249]

God bless you

[@AK-di4rv]

excellent!!!

[@1111thalamus]

Amazing thanks

[@manishshah6385]

thank you ben

[@notsaif7]

helpful, thanks

[@xxanimefanxx11]

for my problem I had to find the overall chemical equation and a rate was given to me. How would I determine if the reaction mechanism is scientifically valid? Or is there a vid I can watch?

[@shrihannalamati7234]

thanks twin

[@Passcase2]

how do you determine which is K1 K2 K3?

[@dudet116]

You just made something that put me on my ass yesterday seem so simple in 10 minutes. You are a God.

[@21DangerousDave]

how about the 2 h2? why didn't you account for k3?

[@SamuelHuang-q8x]

Thanks

[@BensChemVideos]

@SamuelHuang-q8x you're very welcome. Merry Christmas 🎄!

[@manmeetkaur8450]

Thankyou so much :))

[@venushagovender1681]

:) Great help

[@semerekidane9094]

thank you

[@pablocardella5930]

AWESOME!

[@romagnolirojas10]

But since k1 is equal to k-1, since equilibrium can't you just cancel the division since it would be equal to one???

[@eileen02]

Fantastisch!

[@alexawermuth558]

Since k is equal and opposite k-1 can't you just simplify (k1/k-1) to a negative sign?

[@BensChemVideos]

In that first step, k_1 is not equal to k_-1. Rather k_1 * [NO]^2 = k_-1 * [N_2O_2].

[@alexawermuth558]

@@BensChemVideos Thanks!

[@BensChemVideos]

@@alexawermuth558 you bet! Thank you for watching and asking a question!

[@shoryasirohi8724]

Thanks sir

[@ddhchannel6565]

how we will come to know that which reaction is fast or slow

[@gretawilliams8799]

DDH channel
Give your Mom for the answer

[@lukesurey975]

I think they are usually given to you during the test or quiz. If its not, you probably have to determine it experimentally.

[@madisontapia7771]

why isnt k3 used?

[@TheSilversimon]

You didn't account for the consumption of N2O2 in step 2...

[@kaneki1018]

Thanks bruv

[@BensChemVideos]

You're very welcome! Thanks for watching! 😀

[@kickbuttowskiii]

At 3:18, how did you know that the k was k2??

[@uzezistar7407]

why Didn't you write k3 and k2 in the expression?

[@hiranyamalla1648]

what about third step???