If you work with acids and bases, two familiar values are pH and PKA. Here is the definition of the PKA and an overview of its relationship with the strength of acid.
Definition of the PKA:
PK A is the negative logarithm in base 10 of the acid dissociation constant (k a) of a solution.
pka = -log 10 k has more the value of
PK A is weak, the stronger the acid is. For example, the PKA of acetic acid is 4.8, while the pka of lactic acid is 3.8. Using PKA values, we can see that lactic acid is a stronger acid than acetic acid.
The reason for which PKA is used is that it describes acid dissociation using small decimal numbers. The same type of information can be obtained from KA values, but it is generally extremely small numbers given in scientific notation that are difficult to understand for most people.
Key points to remember: definition of the PKA:
- The value of PKA is a method used to indicate the strength of an acid.
- PKA is the negative log of the acid dissociation constant or KA value.
- A lower PKA value indicates a stronger acid. That is to say, the lower value indicates that acid is more completely dissociated into water.
PKA and buffer capacity:
In addition to using the PKA to assess the strength of an acid, it can be used to select stamps. This is possible because of the relationship between PKA and PH:
pH = pka + log 10 ([a -]/[ah])
Where hooks are used to indicate the concentrations of acid and its combined base.
The equation can be rewritten as follows:
K a /[h +] = [a -] /[ah]
This shows that the PKA and the pH are equal when half of the acid has dissociated. The buffer capacity of a species or its ability to maintain the pH of a solution is highest when the values of PKA and PH are close. Thus, when selecting a stamp, the best choice is the one that has a PKA value close to the target pH of the chemical solution.
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