Buffers

MIT RES.TLL-004 Concept Vignettes
Instructor: George Zaidan

In this video, LegosŒ¬ are used to create possible molecular level models of a buffer. This is done to better understand how a buffer works and the components a buffer must contain in order to be effective.

License: Creative Commons BY-NC-SA

[lucytallman]

This is the best explaination of buffers I have ever heard, read or watched.

[mrnulliustestikleezeeastee]

This may be the most lucid explanation of a concept I have ever seen and heard. Sets a new standard.

[prophecyinc.]

Merci Madame Sophie Demoustier de nous avoir fait découvrir cette incroyable vidéo

[ramsayed]

the best explanation ever..It's been 10 years since I have graduated from the school of Medicine with the same questions about Buffer system in the blood & this is the 1st time ever I could really comprehend it.. 
just need one clarification as long as Buffer systems in Blood are basically made by H2CO3 and its same Conjugate base HCO3, not by another base
thanks alot

[mukuntha.g]

it took me 45min to watch this video! My brain didnt handle this much fast paced explanation

[younessbagachoul]

Finally, a good explanation! This was useful. Thanks.

[JonelleDickowVillar]

Beautiful presentation and quality of video. Thank you for your efforts.

[co]

I refreshed my browser at least three times because I thought that the momentary stop right after he added the NaOH was my computer...wait for it....buffering!

[violinsheetmusicblog]

1. H+ reacts with A-, forming HA.
2. OH- reacts with HA forming A-.

They can do this as long as enough HA/A- is present. Once you run out, the buffer stops working...

[maxv]

him: pause the video and discuss with a friend
me, alone in my dorm room: ...

[ChantelJonesCIB]

Thank you, tough material ... well explained with the lego. 

[mrnulliustestikleezeeastee]

I think that what I appreciate the most about this video--perhaps what sets it apart from most or all other on the same topic--is that there is no possible way to misunderstand what is being discussed. There is no ambiguity whatsoever. Brilliant!

[meidianakustyawulandari]

Wow.. it's so amazing. Thanks a lot of your presentation in video. It is enough for understanding for me.

[kris_]

if MIT is explaining it with legos it cant be that hard

[komalmakwana]

Thankyou very much. You have cleared my whole concept

[doyouevengame]

When you say that OH- + HA > H20 + A-, why would this happen as it is a weak acid, to begin with. Would it make sense to say that the OH- reacts with the H+ from the equilibrium established with HA, and then from Le Chatliers Principle, show that the H+ ion concentration in the equilibrium HA > H+ + A- is decreased, and as such more H+ is produced, but only enough to reach the equilibrium. This shows that the H+ ion concentration does not change thus the solution does not change in pH.

[DiegoDiego]

best equilibrum video explening omg so good

[ONLYuseMEgunsOFWALL]

What happens if you add water to a buffert?

[jhinuksaha]

Thanks the explanation was really helpful.

[moristhetiger]

I liked it very much when you asked why should a strong base/acid not act as a buffer, well it made me think.. I came up with an answer that I think does make sense. for the Ka to remain constant.. say [A+][H-]\[HA] A loss in say

So if add OH-


SAY 2% loss of H+ that is numerator will be compensated by decrease in around 2%of the denominator so as to keep the value of [A+][H-]\[HA] constant, , , now since there are a lot less HA in comparisom to H+ the increase of H+ due to decrease of HA that is by dissociation will provide negliable compensation...