Jules Bruno
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Hey, guys, In this new video, we're gonna take our first looks at what exactly is a buffer and how do exactly do they work? So we're gonna say here solutions that contain a weak acid and its conjugate base. Remember when I say weak acid, we could think of HF conjugate base means it has one less h plus. So take off the H plus you have f minus. But professors don't like to give you just f minus. They'll combine that F minus with a metal So we could say our conjugate base here is n A F. So solutions which contain a weak acid like HF and a continent base, has one less h like N A F R called buffer solutions because they resist drastic changes in ph. Now, how do they accomplish this? Well, they do this by keeping your H plus concentration and your O. H minus concentration constant. It keeps them basically the same. The way this works is we're gonna say, adding a small amount off strong base and the pH will increase because remember, if you add base, you're gonna go above seven, so you keep going up and up. But It's not gonna increase by much because the weak acid will neutralize the strong base that you that you add now adding a small amount of strong acid and the pH will decrease again. It's not gonna decrease by much, because why the conjugate base will neutralize what you add. So that's how buffer works. Any acid or base that I add. They get reacted with either the weak acid or the conjugate base. So remember, accident bases are natural enemies of each other. So if I add base, my weak acid steps in to try to take it out. If I add acid, my conjugate base steps up and tries to take it out. That's how a buffer will work. Remember, the only things that could destroy a buffer is by adding too much strong base or too much strong acid. Adding water to a base does nothing to it, well, adding water to not a base, but a buffer does nothing to it. Why? Because adding water would change the concentration of my weak acid. But it also change the concentration of my week based proportionately so proportionately the ratio would stay the same, so my buffer would be unaffected by the addition of water. So remember, adding a strong acid or base is the only way to really destroy buffer. Adding water does nothing to it. Now, knowing this, I want you guys to try to answer this first practice question. We're gonna say which one of the following combinations does not create a buffer. Remember, we just set up above Ah, buffer is a weak acid and it's conjugal base. So this is gonna require you guys to remember the rules that we talked about and identifying compounds and either being acidic or basic, strong or weak. Once you can do that, you'll be able to guide your way to the correct answer for this one. Come back, click on the explanation button and see the choice that I make and see if it matches up with yours.