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Every acid has a constant, called the acid dissociation constant(or Ka), which shows how much the acid dissociates to form ions in water.
For an acid, the general dissociation equation is:
HA -------> H+ + A-
Ka = (concentration of H+) times (concentration of A-) divided by (concentration of HA)
The values for concentrations are the values AT EQUILIBRIUM, where the concentrations of all three substances remain the same.
If HA was a strong acid, it would completely(or almost completely) ionize in water to form its ions. Therefore, you can say that the concentration of H+ ions in the solution equal the concentration of HA. From this, you can calculate the pH by using the formula pH = - log (H+).
If HA was a weak acid, however, things would be different. The acid only partially ionize in water, so you cannot say that the concentration of H+ is equal to the concentration of HA.
If you know the value of the acid dissociation constant, you can easily find the concentration of H+ in the solution, and in turn calculate the pH.
You know that the amounts of H+ and A- are equal. If you know the concentration of the acid HA you put in, you can calculate the H+ .
Wiki User
∙ 13y ago
Wiki User
∙ 11y agoPH= .5 ( pka + pca)
as pka represents dissociation constant of weak acid
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What pH is Cresol?
All three isomers are very weak acids, pKa values varying from 10.26 (o- and p-cresol) to 10.09 (for m-cresol). This means that 1.00 M (standard) solutions in water have pH values of 5.13 to 5.05 (at 25oC).
What are weak acids or weak bases that can react with strong acids or bases to keep the pH?
Solutions containing these mixtures are called buffers.
Can weak acids be precipitated from solutions of their salts by lowering the pH?
Yes this may be possible.
What properties do solutions with high pH values have?
These solutions are basic and can neutralize acids.
Does acid solutions have a pH above 7?
yes all acids have pH below 7 as SUSTANCES HAVING Ph below 7 are acids and that having pH up 7 are bases
Is a solution with a pH of 10.1 a weak acid?
NO... STRONG ACIDS HAVE A pH VALUE BETWEEN 1 AND 4 ....pH VALUES OF 5 AND 6 ARE WEAK ACIDS AND 7 IS NEUTRAL.
If a substance has a pH of 6 is it a strong or werak acid?
Strong acids have pH values below 3 , so it is a weak acid.
What are the pH values of acids Bases?
Acids have pH values below 7.0. Bases have values above 7.0.
What pH does a weak acid have?
Weak acids have a pH around 4-7
What is the lowest pH to the highest pH?
Lowest pH, strong acids, then weak acids, then salts of strong acids and strong bases, then salts of weak acids and strong bases, then weak bases, then strong bases. All very confusing!
How can humans tolerate the extreme pH values of many food and beverage products you consume?
buffers, they help bases and acids to become weak bases and acids. (making the pH not so extreme)
How do you calculate PH of weak acids?
0.75
Which has a lower pH weak acids or strong acids?
strong acid
Would you expect strong acids or weak acids to have a lower pH level?
strong acids
Do strong acids have a higher or lower pH than weak acids?
Weak bases will have a higher H+ concentration.
What is the PH of the weak acid?
weak acids are around 5 and 6 on the pH scale which are things like normal rain
Will concentrated and dilute acids have the same PH reading?
Concentrated and dilute acids will give different pH values
