The question
Name: ______________________ Date: ____________ Ranking acids from their structures (4 points)
Data table
Three oxyacids and a carboxylic acid
Structures are shown with the acidic hydrogen bonded to oxygen.
| Acid | Structure | Ka |
|---|---|---|
| Hypochlorous acid | H–O–Cl | 3.0 × 10⁻⁸ |
| Hypoiodous acid | H–O–I | 2.3 × 10⁻¹¹ |
| Acetic acid | CH₃–C(=O)–O–H | 1.8 × 10⁻⁵ |
| Trifluoroacetic acid | CF₃–C(=O)–O–H | 0.59 |
(a) HOCl is a stronger acid than HOI. Explain why, in terms of molecular structure. [1 point]
(b) Trifluoroacetic acid is a much stronger acid than acetic acid. Explain why. [1 point]
(c) Equal concentrations of NaOCl and NaOI are prepared. Identify the solution with the higher pH. Justify your answer. [1 point]
(d) Calculate the pH of 0.10 M HOCl. [1 point]