So a buffer is just basically a weak acid with its conjugate base. Great example we have H. C. L. O. Which is hipaa Cloris acid, this is a week oxy acid here when we talk about a conjugate base that is the same form as the weak acid except it has one less hydrogen and that hydrogen that it's missing is typically replaced with a metal. Usually from group one A. So Hipaa Clorox acid is H. C. L. O. And here we have sodium hypochlorite. The hydrogen has been replaced with a metal so we have a weak acid and its conjugate base together. They form a buffer. Now a buffer hot. What does it do? Well it causes my solution to resist big changes in ph it does this by keeping constant both my H plus ions and my hydroxide ions. It tries to keep them around the same level as much as possible and for as long as possible. Great example is the buffer system within our blood which is composed of carbonic acid and bicarbonate. Without this our blood would become very acidic or very basic depending on what we're drinking soda for example is very acidic. Without a buffer system in our blood our blood will become incredibly acidic pretty quickly just from a can of soda. Now how does it do this? Well remember our buffer is composed of a weak acid and a conjugate base so if we add strong base to our solution to our buffer solution then the buffer resists a ph change by having the weak acid neutralize it. Remember acids and bases are natural um I don't want to say enemies but their natural opposites of one another. If if they're both present together in the same space they try to neutralize one another. So by adding strong base the weak acid steps up to try to get rid of it. So here we have still our weak acid are hipaa Cloris acid. I add some N. A. O. H. Strong base. Here we undergo a neutralization reaction where we create sodium hypochlorite which is some of my conjugate base which is great because these two will be in existence with each other in solution if there's not a lot of N. A. O. H. And therefore stabilize my buffer plus water. If I had strong acid. What happens? Well if I had strong acid then the other part of my buffer, the conjugate base steps up to neutralize that. So here now the conjugate base steps up sodium hypochlorite steps up and tries to neutralize the hcl, thereby creating more weak acid. So more component of my buffer to help stabilize the ph Now here's the thing, the weak acid and the conjugate base can't keep this up forever. So the more strong acid and the more strong base you add the weaker the buffer is going to get because these two are neutralizing each other and these two are neutralizing each other add too much of this and then all of this will be gone and without a weak acid present, you would no longer have a buffer. All you'd have is conjugate base, add too much of the strong acid and you would destroy your conjugate base. Therefore you would no longer have a buffer because all you have left is weak acid being produced. So a buffer resists large changes in ph by stepping up and counteracting when a strong acid or a strong base is added up to a certain point. So these are the fundamentals of what a buffer is. Click on the next video where we can talk about what are the best ranges for which a buffer can operate.
