Asked in
Chemistry
Acids and Bases
Mathematical Constants

How do you calculate a dissociation constant?

Answer

User Avatar
Wiki User
November 28, 2007 2:08AM

Determination of the Dissociation Constant and Molar Mass for a Weak Acid

Abstract: We will determine Ka and the molar mass for an unknown weak acid by using a pH meter to record the pH at intervals during the titration with sodium hydroxide. The titration curve and its first derivative will be plotted to establish the equivalence point. Introduction The strength of an acid is defined by its ability to donate a proton to a base. For many common acids, we can quantify acid strength by expressing it as the equilibrium constant for the reaction in which the acid donates a proton to the standard base, water, as shown in the equations below: HA + H2O Û H3O+ + A-, for H3CCOOH: H3CCOOH + H2O Û H3O+ + H3CCOO - The equilibrium constant for a reaction of this type is called the Acid Dissociation Constant, "Ka", for the acid HA Determination of the Dissociation Constant and Molar Mass for a Weak Acid

Abstract: We will determine Ka and the molar mass for an unknown weak acid by using a pH meter to record the pH at intervals during the titration with sodium hydroxide. The titration curve and its first derivative will be plotted to establish the equivalence point. Introduction The strength of an acid is defined by its ability to donate a proton to a base. For many common acids, we can quantify acid strength by expressing it as the equilibrium constant for the reaction in which the acid donates a proton to the standard base, water, as shown in the equations below: HA + H2O Û H3O+ + A-, for H3CCOOH: H3CCOOH + H2O Û H3O+ + H3CCOO - The equilibrium constant for a reaction of this type is called the Acid Dissociation Constant, "Ka", for the acid HA Determination of the Dissociation Constant and Molar Mass for a Weak Acid

Abstract: We will determine Ka and the molar mass for an unknown weak acid by using a pH meter to record the pH at intervals during the titration with sodium hydroxide. The titration curve and its first derivative will be plotted to establish the equivalence point. Introduction The strength of an acid is defined by its ability to donate a proton to a base. For many common acids, we can quantify acid strength by expressing it as the equilibrium constant for the reaction in which the acid donates a proton to the standard base, water, as shown in the equations below: HA + H2O Û H3O+ + A-, for H3CCOOH: H3CCOOH + H2O Û H3O+ + H3CCOO - The equilibrium constant for a reaction of this type is called the Acid Dissociation Constant, "Ka", for the acid HA