What is the value of acid dissociation constant (Ka) for the weak acid HZ?
The value of Ka for the weak acid HZ is approximately 4.28 × 10⁻⁹, calculated using the given pH of 4.28 and concentration of HZ as 0.60 mol/L. Ka represents the acid dissociation constant and reflects the extent of acid dissociation in solution.
Understanding Acid Dissociation Constant (Ka)
Acid dissociation constant (Ka) is a quantitative measure of the strength of an acid in a solution. It indicates the degree to which an acid ionizes when dissolved in water. In the case of a weak acid like HZ, Ka helps determine the extent of its dissociation into hydrogen ions (H⁺) and conjugate base ions (Z⁻).
Calculating Ka for Weak Acid HZ
To find the value of Ka for the weak acid HZ, we start by using the pH of the solution, which is 4.28. The pH is related to the concentration of H⁺ ions in the solution, determined by the dissociation of the weak acid.
The pH is defined as the negative logarithm (base 10) of the H⁺ concentration: