So we've understood the fundamentals when it comes to buffers but what classifies a good buffer versus a bad buffer. Doesn't really matter what the proportions of weak acid are to to conjugate base. Well in reality yes it does matter. We're gonna say the weak acid and conjugate base can be different from one another by up to a magnitude of 10. We're gonna say that this is called the buffer range. If they're different by more than a magnitude of 10 then it will not be a buffer. So remember with buffers we have a conjugate base to weak acid ratio. So we're gonna say conjugate base CB two weak acid ratio. They can't be more than a magnitude of 10 away from each other. So how do I check to see if they are you would just say conjugate base to weak acid is just conjugate base over weak acid at most. That can be different by up to a magnitude of 10. Which means that conjugate base could be one, weak acid could be up to 10. So this is 100.10 Or conjugate base weak acid conjugate bases, 10 weak acid is one. So this is 10. So when we say a buffer range in a magnitude of 10. That means a range when we do conjugate base over weak acid. When we plug in the numbers for each one they have to lie between .10 And up to 10. Okay, so they have to fall within that range. If the conjugate base to weak acid ratio is outside these numbers then it is not a good buffer. And in fact we may we can say that although it looks like we have a weak acid and conjugate base, it does not constitute a buffer because the range the ratio doesn't give me a value of 0.10 to 10. So remember just do conjugate base over weak acid and put the values that you're given and see do they lie between 100.10 and 10? So if we take a look at this example we have one molar of our week oxy acid and 0.10 of our conjugate base here are weak acid is 10 times the amount of the conjugate base. So it's at an exact limit can't be more than 10 fold difference between the both of them, they've reached their maximum, you would do conjugate base over weak acid if you wanted and you can see how that stacks up and yes we get 0.10 which is within that range of 0.10 to 10 Here for this one. Now I've changed up the concentration so now it's .05 molar of my weak acid and 10.50 Moeller of my conjugate base. So my conjugate base to a weak acid ratio So that equals 10. Yes, again we fall within this range. So anytime you're given a weak acid and its conjugate base with amounts you can check to see does it lie within the right buffer range? If it doesn't it doesn't constitute a buffer. Now that we've learned about buffer range, click on to the final video to learn about one more requirement when it comes to being a good effective buffer.
