Answer:
2.16 × 10⁻³
Explanation:
Step 1: Given data
Concentration of the acid (Ca): 0.260 M
Acid dissociation constant (Ka): 1.80 × 10⁻⁵
Step 2: Write the acid dissociation equation
HC₂H₃O₂(aq) + H₂O(l) ⇄ C₂H₃O₂⁻(aq) + H₃O⁺(aq)
Step 3: Calculate the concentration of H₃O⁺ at equilibrium
We will use the following expression.
[tex][H_3O^{+} ]= \sqrt{Ka \times Ca } = \sqrt{1.80 \times 10^{-5} \times 0.260 } = 2.16 \times 10^{-3}[/tex]