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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+ .
What else can I help you with?
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.
Does the addition of water (baking soda plus water) alter the pH of weak acidsbasesHow does it changethe pH of srong acidsbases Why or why not?
The addition of water to weak acids or bases generally dilutes the solution, which can lead to a slight increase in pH for weak acids and a decrease in pH for weak bases due to the equilibrium shifting. In contrast, adding water to strong acids or bases typically results in a more significant change in pH, as strong acids and bases dissociate completely in solution. Therefore, dilution with water for strong acids will lower the pH (less acidic) and for strong bases will raise the pH (less basic) but will still remain strongly acidic or basic depending on their original concentration. Overall, the extent of pH change depends on the strength and concentration of the acid or base involved.
Can weak acids be precipitated from solutions of their salts by lowering the pH?
Yes this may be possible.
Does weak acid always act to change the pH when placed in water?
No, weak acids do not always significantly change the pH of a solution when placed in water. The extent to which a weak acid affects pH depends on its concentration and the properties of the buffer system in the solution. In some cases, weak acids may only have a minor effect on pH due to the presence of other components that resist pH changes.
Are weak acids on the pH scale less than 3?
NO!!!! The pH scale is from 0 to 14. The lower the numerical value of the pH , then the stronger the acid. e.g. pH = 1 Strongly acidic ( e.g. Hydrochloric Acid). pH = 4 Weakly acidic ( e.g. Ethanoic (Acetic) acid). pH = 7 Neutrality (Water) pH = 9 Weakly Alkaline ( Ammonia Solution). pH = 12 Strongly Alkaline ( Sodium Hydroxide). pH = 14 Very strongly alkaline ( very weakly acidic ; in extremis). NB The pH is the 'negative logarithm , to the base 10, of the hydrogen ion conc'n. Algebraically ; pH = -(log(10)[H^(+)]) The inverse maths. function is [H^(+)] = 10^(-pH). So if you have a pH = 1 Then H^(+) = 10^(-1) = 0.1 ( Casually a tenth of the sol'n is hydrogen ions). If you have a pH = 12 Then H^(+) = 10^(-12) = 0.000000000001 (Casually a trillionth of the solution is hydrogen ions; usually considered as strongly alkaline with a pOH = 0.01, an hundredth of the solution is hydroxide ions, compared to a trillionth( an extremely tiny amount), of hydrogen ions.
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.
Acids pH range between what two numbers?
Acids typically have a pH range between 0 and 7. A pH of 7 is considered neutral, while values below 7 indicate increasing acidity. Strong acids can have pH values close to 0, while weak acids will have pH values closer to 7 but still below it.
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.
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)
What is the ph value of acids?
1-6 1- Strong Acids 6- Weaker Acids
What are the pH values of acids Bases?
Acids have pH values below 7.0. Bases have values above 7.0.
What is the pH of diluted carboxylic acid?
The pH of diluted carboxylic acids can vary depending on the specific acid and its concentration. Carboxylic acids typically have pH values in the range of 2 to 5 when diluted in water. The presence of the carboxyl group (COOH) in carboxylic acids causes them to be weak acids, leading to slightly acidic pH values when diluted.
PH of acid is?
Different acids have different pH levels. The pH scale is a measure of acidity of any substance; a pH of 7 is neutral, anything with a pH lower than 7 is acidic. For example: lemons pH is about 2.2
Which has a lower pH weak acids or strong acids?
pH = 0 to 2 is a STRONG acid. ( e.g. Hydrochloric Acid) pH = 3 to 6 is a WEAK acid. ( e.g. Ethanoic (Acetic) acid). NB THe greater the numerical value of the pH , then the weaker the acid.
Do strong acids have a higher or lower pH than weak acids?
Strong acids have a lower pH than weak acids. This is because strong acids completely dissociate in water to release all their hydrogen ions, resulting in a high concentration of H+ ions and a lower pH. Weak acids only partially dissociate, leading to a lower concentration of H+ ions and a higher pH.
Does a weak acid resist a change in the pH?
NO!!! A 'Buffer Solution'., resists a change in pH. A Buffer Solution is a solution of the weak acid and its corresponding salt. e.g. Ethanoic Acid and Sodium Ethanoate. The ethanoic acid only partially dissociates in to ;_ CH3COOH < ====- > CH3COO^(-) + H^(+) The sodium ethanoate fully dissociates CH3COONa ====> CH3COO^(-) + Na^(+) If you add a small quantity of hydrogen ion H^(+), then these ion will reassociate with the 'excess' ethanoate ions from the sodium ethanoate. Thereby reducing the number of hydrogen ions in solution, hence the pH changes by only a very small amount ; it is described as 'resisting a change of pH'.
