Answer:
1.43 × 10⁻¹¹
Explanation:
Step 1: Given data
- Concentration of the weak acid (Ca): 0.440 M
- pH of the solution: 5.600
Step 2: Calculate the concentration of H⁺
We will use the definition of pH.
pH = -log [H⁺]
[H⁺] = antilog -pH = antilog -5.600 = 2.512 × 10⁻⁶ M
Step 3: Calculate the acid dissociation constant (Ka)
For a weak acid, we can calculate Ka using the following expression.
Ka = [H⁺]²/Ca
Ka = (2.512 × 10⁻⁶)²/0.440 = 1.43 × 10⁻¹¹
