What is acid dissociation constant?

 Hello fam, today we are going to move further on the concept that we were trying to develop yesterday. Remember that yesterday we saw that the equilibrium constant shows us the extent to which reactants are converted into products.


We are going to develop this concept in detail as we progress in this study. Now let us go back to the idea of strong and weak acids. We agreed that a strong acid dissociates completely in solution while a weak acid does not dissociate to a reasonable extent in solution.


We have also established that the degree of dissociation of an acid can be expressed as a percentage. We would pick up on this point later in the series.


Since a strong acid dissociates completely in solution,there is no need to study the degree to which the acid dissociates. All the ions in the strong acid gets into solution and the molecule of the acid is simply no more!


In the case of the weak acid, we want to know just how much of the weak acid is dissociated in solution. This would give us an idea concerning how much of the original molecules of the acid that still remains in the solution without being dissociated. 


Like I said previously, there has to be a value that would give us that information. 


The value that shows the extent to which a weak acid is ionized or dissociated in solution is called the acid dissociation constant.


The acid dissociation constant is a measure of the strength of an acid in solution. It shows us the extent to which the forward reaction (dissociation of the ions in the acid) occurs. 


Remember that when we talk about the 'strength' of an acid, we are not referring to how dangerous the acid is. We are simply referring to how much the original acid molecules can break up when dissolved in water to give the ions that compose the acid when in solution.


If the acid breaks up to a large extent to form ions in solution, then the acid is strong. If the acid does not break up to a large extent to form ions in solution, then the acid is weak.


In tomorrow's lesson, we are going to look deeper into this idea of the acid dissociation constant and how the equilibrium constant (K) for the dissociation of an acid in solution is obtained. stay tunned!


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