15.2 Le Chatelier's Principle | General Chemistry

Chad provides a comprehensive lesson on Le Chatelier's Principle which states that if a stress is placed on a system at equilibrium, the system will respond to counteract the stress. If you're at all struggling with this concept, then check out this lesson as Chad explains Le Chatelier's Principle from 3 different perspectives: based upon the definition, by comparing the reaction quotient (Q) to the equilibrium constant (K), and by comparing the forward rate to the reverse rate. They all reinforce each other to help the student correctly predict whether a system will shift left or shift right including how to predict temperature and pressure effects.
I've embedded this playlist as a course on my website with all the lessons organized by chapter in a collapsible menu and much of the content from the study guide included on the page. Check this lesson out at www.chadsprep.com/chads-gener...
If you want all my study guides, quizzes, final exam reviews, and practice exams, check out my General Chemistry Master Course (free trial available) at www.chadsprep.com/genchem-you...
00:00 Lesson Introduction
00:28 Introduction to Le Chatelier's Principle
01:10 The Reactions Quotient and Comparing Q to K
06:14 Adding a Reactant (Shift Right)
09:21 Removing a Product (Shift Right)
12:15 Adding a Solid (No Shift)
13:41 Changing the Temperature
17:52 Changing the Pressure
21:24 Adding an Inert Gas
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Пікірлер: 58

  • @beagonzales8918
    @beagonzales8918 Жыл бұрын

    HOW IS CHAD NOT MONETIZED??? He's literally the best! I've been having a hard time understanding what happens if the pressure is changed and this is the only video that helped me. Binging his other videos!

  • @ChadsPrep

    @ChadsPrep

    Жыл бұрын

    Happy Studying!

  • @mambo5431
    @mambo54315 ай бұрын

    i just want to let you know that youre helping out people (like me just now) with your videos to this day

  • @ChadsPrep

    @ChadsPrep

    5 ай бұрын

    Glad to hear it - Happy Studying!

  • @itsdhrubo9011
    @itsdhrubo90112 жыл бұрын

    It is hard to get such quality lectures on KZread. Very well explained and hope you will keep up the good work...

  • @ChadsPrep

    @ChadsPrep

    2 жыл бұрын

    Glad the channel/videos are helping you!

  • @ashleem3295
    @ashleem3295 Жыл бұрын

    I am so thankful I found your videos! You are a great teacher, and I wish I had found you in gen chem 1! I love that you take the time to teach each aspect of the section. My professor teaches quickly and skips many small steps, so your videos help me actually learn the material.

  • @ChadsPrep

    @ChadsPrep

    Жыл бұрын

    Glad the channel/videos are helping you - Happy Studying!

  • @ConnorStear
    @ConnorStear5 ай бұрын

    I had to stop and applaud how beautifully simple you made everything right around the range of 3:40 to 4:40. Everything clicked so well it's like I could feel the neurons firing in my brain lol.

  • @ChadsPrep

    @ChadsPrep

    5 ай бұрын

    I am happy for your brain expansion! Thanks for saying so!

  • @saqibkhan3364
    @saqibkhan3364 Жыл бұрын

    Chad, In the last lecture you said that only temperature can change the equilibrium constant. So it is fair to say that when we are are changing the concentration of reactants and products, we are not changing the equilibrium constant but rather the reaction quotient. So when we change the reaction quotient, this shifts the reaction in a way that allows us to get back to the equilibrium constant which remains the same value because only temperature can change the equilibrium constant? (I hope this makes sense).

  • @ChadsPrep

    @ChadsPrep

    Жыл бұрын

    Exactly right Saqib! I can't tell you how confusing many students find this, but you've got it!

  • @life0fjah
    @life0fjah8 ай бұрын

    youre the best man, you explain things so well! THANK YOU!

  • @ChadsPrep

    @ChadsPrep

    8 ай бұрын

    You're welcome and Thank You.

  • @user-vl1bk9jh4h
    @user-vl1bk9jh4h6 ай бұрын

    Sir l know you are the only teacher who can clear away my all confusions relevant to my questions😢

  • @kimberlysanchez6693
    @kimberlysanchez669311 ай бұрын

    Thank you so much!!!! Been watching all of your chem videos

  • @ChadsPrep

    @ChadsPrep

    11 ай бұрын

    Glad to hear - Happy Studying!

  • @devikanair44
    @devikanair442 жыл бұрын

    thank you so much for explaining the effects with temperature. I was struggling with that for a long time b/c I was confused how shifting T changes a rxn b/c it affects equilibrium. One quick question! how would you reconcile that delta G = -RTlnK but if you added heat in an exothermic reaction the delta G should be less negative, but according to the formula if you increase temperature the Delta G would be more negative? loving the new playlist!!

  • @ChadsPrep

    @ChadsPrep

    2 жыл бұрын

    Hey Devika - The equation ΔG° = -RT ln K is for standard delta G only, and if we increase the temperature we are no longer at standard conditions and this equation doesn't apply. Instead, if you look at the equation ΔG = ΔH-TΔS and consider that an exothermic reaction has negative ΔH then the value of ΔS will determine whether ΔG is positive or negative overall

  • @destinycross7977
    @destinycross79772 жыл бұрын

    Hi, you said shifting to the right causes the Q value to go up, I thought it causes it to go down since it Q

  • @user-fk8yu7wf7c
    @user-fk8yu7wf7c3 ай бұрын

    Do pressure and volume affect the equilibrium constant? If they don't affect it, how? I got confused about it Especially when I was watching the clip at minute 19

  • @agentsikagwenu6049
    @agentsikagwenu6049 Жыл бұрын

    Job well done ✅✅✅ God bless you

  • @ChadsPrep

    @ChadsPrep

    Жыл бұрын

    Thank you!

  • @destinycross7977
    @destinycross79772 жыл бұрын

    why would we shift Co to right and not left to decrease Co?

  • @DavidElks-qh2pn
    @DavidElks-qh2pn3 ай бұрын

    You are truly a life savior ❤❤

  • @ChadsPrep

    @ChadsPrep

    3 ай бұрын

    Wow - thank you!

  • @jeremyalex7678
    @jeremyalex7678 Жыл бұрын

    best lecture✊

  • @ChadsPrep

    @ChadsPrep

    Жыл бұрын

    Thank you!

  • @user-vl1bk9jh4h
    @user-vl1bk9jh4h6 ай бұрын

    Dear sir you asked that change in conc of either reactants or products at eq doesn't affect the value of Kc but if we increase the conc of O2 here the reaction will go in forward direction and reverse reaction remains unchanged and after a second the consumption of extra O2 again rate of forward reaction also becomes slow down and both rates again become equal . In other hand if at eq we decrease the conc of Co the reaction will go in forward direction but in this case we have no extra addition of reactants or products but our normally present reactants at eq are consuming and in this case the rate of reverse reaction slow down and after a second both the rates again become equal sir how both these reactions could have equal value of Kc😢😢😢😢

  • @user-vl1bk9jh4h
    @user-vl1bk9jh4h6 ай бұрын

    Sir can a Q become greater than Kc before we reach eq

  • @jbean22941
    @jbean229414 ай бұрын

    thank you

  • @ChadsPrep

    @ChadsPrep

    3 ай бұрын

    you're welcome

  • @clomes9200
    @clomes92008 ай бұрын

    this guys the goat

  • @ChadsPrep

    @ChadsPrep

    8 ай бұрын

    Thanks!

  • @saqibkhan3364
    @saqibkhan3364 Жыл бұрын

    Another Question, What if we decrease the pressure by increasing the volume? How would this effect the shift of the rxn?

  • @ChadsPrep

    @ChadsPrep

    Жыл бұрын

    Saqib, if you increase the volume, you lower the concentration of all species (since molarity is mol/L). Now if you have an equal number of moles of gas on both sides of the reaction, it won't shift as Q would not change. But if they are not equal, then Q will change and the reaction will shift to the point where Q is equal to K again. Overall, by increasing the volume to lower the pressure it will shift toward whichever side has the greater number of moles of gas. Hope this helps!

  • @dawithabteselassie7116
    @dawithabteselassie71163 ай бұрын

    is the universe in equilibrium applying Le Chatlier principle?

  • @ChadsPrep

    @ChadsPrep

    3 ай бұрын

    If it were, then you and I wouldn't be here to discuss it!

  • @user-fk8yu7wf7c
    @user-fk8yu7wf7c3 ай бұрын

    All three changes: 1- Withdrawing or adding to the interaction 2-Change the volume or pressure 3- Changing the reaction temperature It will change with the concentrations of substances for the equilibrium reaction Why is it only temperature that changes the value of the equilibrium constant?

  • @user-vl1bk9jh4h
    @user-vl1bk9jh4h7 ай бұрын

    Sir Q is greater than Kc means that we are talking about before eq and if Q is smaller than Kc means that we are talking about after eq because after eq l think we should have a lower conc of products and higher conc of reactants but sir we also say that once the reaction reached eq with the passage of time there is a constant change in the conc of products and reactants how this happens ???? I am totally confused sir😢😢😢😢

  • @user-vl1bk9jh4h

    @user-vl1bk9jh4h

    7 ай бұрын

    Sir how can I understand it????

  • @RelaxRailRide
    @RelaxRailRide2 жыл бұрын

    Sir, what is your age and marital status?

  • @ChadsPrep

    @ChadsPrep

    2 жыл бұрын

    I'm pretty old regarding the first question and happily married regarding the second.😊

  • @RelaxRailRide

    @RelaxRailRide

    2 жыл бұрын

    @@ChadsPrep 😇

  • @mabotiyn
    @mabotiyn9 ай бұрын

    Chad I have a question

  • @user-vl1bk9jh4h
    @user-vl1bk9jh4h6 ай бұрын

    I just cut off your answer before looking at it unfortunately

  • @user-vl1bk9jh4h
    @user-vl1bk9jh4h6 ай бұрын

    Sir you also said that stochimetric cofficients do effect the value of Kc but now you are saying that if we increase or decrease the conc of reactants or products at eq mean we increase or decrease the number of moles of reactants or products the value of Kc will not change ????? 😢😢😢😢how sir?????

  • @ChadsPrep

    @ChadsPrep

    6 ай бұрын

    The idea is that the ratio of products to reactants is only equal to Kc if the reaction is at equilibrium, whereas we can always say that the ratio is equal to Q, whether the reaction is at equilibrium or not. So if the reaction is at equilibrium, then the ratio of products to reactants will equal both Kc and Q (as Q=Kc at equilibrium). But if change the concentration of a reactant or a product, then at that instant the reaction will no longer be at equilibrium, and the ratio of products to reactants will still equal Q by definition, but it will not equal Kc (since the reaction is not at equilibrium). But you could also look at the situation mathematically and say that this is why the reaction will shift...in order to get back to equilibrium. If the altering of the concentration resulted in Q Kc, then the reaction will shift to the left until we once again reach equilibrium and Q = Kc again. Ultimately, changing a concentration does change the ratio and this changes Q, but not Kc (as a reminder the only thing that results in a change in Kc is a change in temperature). Hope this helps!

  • @user-vl1bk9jh4h

    @user-vl1bk9jh4h

    6 ай бұрын

    @@ChadsPrep Thanks alot dear professor l just understand it

  • @ChadsPrep

    @ChadsPrep

    6 ай бұрын

    @@user-vl1bk9jh4h Glad to hear!

  • @destinycross7977
    @destinycross79772 жыл бұрын

    Im sorry I am so confused. I really need help

  • @etodd1234
    @etodd1234 Жыл бұрын

    I was under the assumption that an increase in temperature always caused a rightward shift and vice versa for a decrease in temperature...

  • @ChadsPrep

    @ChadsPrep

    Жыл бұрын

    Not true; it absolutely depends upon whether the reaction is endo- or exothermic. However, you may be thinking about the RATE of reaction as the reaction will be faster at higher temperatures...but so will the reverse reaction. So generally a reaction will proceed to equilibrium more quickly at higher temperatures, but whether or not it shifts left or right again depends upon whether it is endo- or exothermic. Hope this helps!

  • @user-vl1bk9jh4h
    @user-vl1bk9jh4h6 ай бұрын

    Waiting for your reply sir??????

  • @user-vl1bk9jh4h
    @user-vl1bk9jh4h6 ай бұрын

    Sir g sorry plz reply again 😮

  • @ChadsPrep

    @ChadsPrep

    6 ай бұрын

    what are you struggling with?

  • @user-vl1bk9jh4h

    @user-vl1bk9jh4h

    6 ай бұрын

    Sir I want to become a doctor and l don't understand your question and sir lam waiting for your answers about my questions sir did you see my questions which I asked About your topic?

  • @mathewhorodner2000

    @mathewhorodner2000

    3 ай бұрын

    @@ChadsPrep @user-vl1bk9jh4h 3 months ago Dear sir you asked that change in conc of either reactants or products at eq doesn't affect the value of Kc but if we increase the conc of O2 here the reaction will go in forward direction and reverse reaction remains unchanged and after a second the consumption of extra O2 again rate of forward reaction also becomes slow down and both rates again become equal . In other hand if at eq we decrease the conc of Co the reaction will go in forward direction but in this case we have no extra addition of reactants or products but our normally present reactants at eq are consuming and in this case the rate of reverse reaction slow down and after a second both the rates again become equal sir how both these reactions could have equal value of Kc.......... @user-vl1bk9jh4h 3 months ago Sir Q is greater than Kc means that we are talking about before eq and if Q is smaller than Kc means that we are talking about after eq because after eq l think we should have a lower conc of products and higher conc of reactants but sir we also say that once the reaction reached eq with the passage of time there is a constant change in the conc of products and reactants how this happens ???? I am totally confused sir This is from @user-vl1bk9jh4h