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In water, measurable pK a values range from about −2 for a strong acid to about 12 for a very weak acid (or strong base). A buffer solution of a desired pH can be prepared as a mixture of a weak acid and its conjugate base. In practice, the mixture can be created by dissolving the acid in water, and adding the requisite amount of strong acid ...
The strength of a weak acid is quantified by its acid dissociation constant, value. The strength of a weak organic acid may depend on substituent effects. The strength of an inorganic acid is dependent on the oxidation state for the atom to which the proton may be attached. Acid strength is solvent-dependent. For example, hydrogen chloride is a ...
Any acid with a pK a less than about −2 is said to be a strong acid. Strong acids are said to be fully dissociated. Strong acids are said to be fully dissociated. There is no precise p K a value that distinguishes between strong and weak acids because strong acids, such as sulfuric acid , are associated in very concentrated solution.
Strong acids, such as sulfuric or phosphoric acid, have large dissociation constants; weak acids, such as acetic acid, have small dissociation constants. The symbol K a , used for the acid dissociation constant, can lead to confusion with the association constant , and it may be necessary to see the reaction or the equilibrium expression to ...
The Henderson–Hasselbalch equation relates the pH of a solution containing a mixture of the two components to the acid dissociation constant, K a of the acid, and the concentrations of the species in solution. [6] Simulated titration of an acidified solution of a weak acid (pK a = 4.7) with alkali
When some strong acid is added to an equilibrium mixture of the weak acid and its conjugate base, hydrogen ions (H +) are added, and the equilibrium is shifted to the left, in accordance with Le Chatelier's principle. Because of this, the hydrogen ion concentration increases by less than the amount expected for the quantity of strong acid added.
A weak base will have a higher H + concentration than a stronger base because it is less completely protonated than a stronger base and, therefore, more hydrogen ions remain in its solution. Given its greater H + concentration, the formula yields a lower pH value for the weak base.
and then, acting as a weak acid, hydrogen phthalate reacts reversibly with water to give hydronium (H 3 O +) and phthalate ions. HP − + H 2 O ⇌ P 2− + H 3 O + KHP can be used as a buffering agent in combination with hydrochloric acid (HCl) or sodium hydroxide (NaOH). The buffering region is dependent upon the pKa, and is typically +/- 1.0 ...