15.3 Equilibrium Calculations

[@matsallehrambutputih3745]

Chad, you are to me a sensational teacher. You cover the bits and pieces that most others miss because they probably haven't thought about it as deeply as you. I'm a 50 yr-old career-changer about to become a trainee chemistry/science teacher and from the other side of the globe I shall be largely hoping to mimic your style. Fan-tas-tic and thanks.

[@ChadsPrep]

You're so welcome and good luck with your career change :)

[@pinkiepie379]

Thank you so much for these videos! Way more concise and clear with the materials than my class is, definitely helped me with studying. ^^

[@ChadsPrep]

Awesome! Glad you're finding them helpful!

[@kimberlyfrye830]

How do you make things that I already understand somehow easier to understand?! I just...thank you so much for these videos and the website. I'm not sure how you do it, but you explain it in a way that is 10000000% easier to understand than lecture/book. Thank you!

[@ChadsPrep]

You are welcome, Kimberly - glad you find them helpful!

[@anthonyd5643]

Great teacher! Thank you much. I will be using your videos as I retake my premed requirements

[@ChadsPrep]

Glad to hear the videos are helpful, Dwight - good luck!

[@sherrymagdy8]

THANK YOU CHAD for ALL your helpful Ochem and Chem videos, I recommend you to all my friends! I have a quick question: how do you know the initial values and when to assume that its zero? Thanks in advance

[@ChadsPrep]

You're very welcome Sherry! The initial concentrations must be provided. It is not uncommon for a question to say that initially there is only 'x' in the container which means that the initial concentration of all other species is zero. This is most common for starting with only reactants and therefore zero products. Hope this helps!

[@sherrymagdy8]

@@ChadsPrep Thank you so much for clarifying, it makes more sense now!

[@ChadsPrep]

@@sherrymagdy8 Glad to hear it!

[@purbasimran]

At 2:20, you said reaction has to go to the right because we start with 0M HCl. At 12:50, you concluded that K

[@ChadsPrep]

These were two different problems involving the same reaction. The initial problem started with zero HCl. With no product present the reaction cannot proceed in the reverse direction. But at 10:10 I proposed a second question. In that question I provided initial concentrations for all the reactants and products. Because both reactants and products were both present we couldn't very quickly know which way the reaction needed to proceed to reach equilibrium. We had to calculation the reaction quotient, Q, and compare it to the equilibrium constant, K. In this 2nd question we determined that K < Q and therefore the reaction needed to proceed left to reach equilibrium. Hope this helps to clarify!

[@purbasimran]

@@ChadsPrep Thank you so much!

[@dankeller2590]

Hi Chad, At 20:40, you mentioned that because the Keq was very small, the reactants are favored. Am I good to justify that statement with the following logic? Since the Keq is ([products]/[reactants]) and since Keq is small, we must have higher [reactants] than [products] at equilibrium. This means to reach equilibrium, the reaction will favor the formation of more reactants. Thank you!

[@ChadsPrep]

You could say that since Keq is small there will be more reactants than products at equilibrium (this is what we mean when we say the reactants are favored). But be careful on the declaration of what must take place to reach equilibrium as this depends upon not only on the ratio of products to reactants at equilibrium (Keq) but also on the ratio you have now (Q...reaction quotient). If the ratio you have now is greater than the ratio at equilibrium (Q > K) then the reaction will proceed to the left to form reactants to reach equilibrium. But if the ratio you have now is less than the ratio at equilibrium (Q < K) then the reaction will proceed to the right to form products to reach equilibrium. Hope this helps!

[@satchelkrawchuk8640]

Chad is the 🐐

[@ChadsPrep]

Don't think I've been called that before, but if it is good, I accept! Hope you find the videos helpful!

[@satchelkrawchuk8640]

@@ChadsPrep Goat = GreatestOfAllTime , so yes hahah! Amazing videos, really solidifying my past chemistry knowledge in preparation for my DAT. Thank you!

[@ChadsPrep]

AH!! Thanks for the clarification - always glad to hear how our videos are helping folks. Good luck on your DAT!

[@triple_gem_shining]

@@ChadsPrep xD love it

[@ChadsPrep]

@@triple_gem_shining Excellent!

[@changbinaa997]

Thank u very much Sir

[@ChadsPrep]

Most welcome

[@jigarpatel9912]

Hi Chad, I was wondering how you got the initial concentrations on both questions. Thanks!

[@ChadsPrep]

Sorry Jigar, they were supplied in both questions. The students attending the lecture in person had the accompanying study guide with the questions on it. The study guide is included with my premium course on chadsprep.com fyi. Best in your studies!

[@deborahaigbedion6323]

how do you know when the reactants are favored or the products are favored? where will it shift?

[@ChadsPrep]

Hi Deborah! You can look at the value of K since K is the ratio of products to reactants: If K>1, the products are favored. If the and if K

[@SpareLs]

0:38 Mastering Chemistry...I never wanted to hear any science following the word "Mastering" ever again

[@ChadsPrep]

Embrace the challenge!

[@shayanahmed4598]

No one : Chad : Cool

[@ChadsPrep]

😀 😃 😀

[@shayanahmed4598]

@@ChadsPrep love your attitude professor, you teach me alot and for that I am grateful!

[@ChadsPrep]

Excellent, Shayan Ahmed - Happy Studying!

[@jjpeacelover101]

You are far from insignificant

[@ChadsPrep]

😊😊😊