Topic: Acids and Bases
Your central place for worksheets, question banks, videos, and more.
Past Exam Questions
Practice Test
Deep Thinking Challenges
Reading Beyond A-Level
The pKₐ values of ethanol ($\approx 16$), phenol ($\approx 10$), and ethanoic acid ($\approx 5$) show a dramatic increase in acidity. According to Brønsted-Lowry theory, acid strength is determined by the stability of the resulting conjugate base after a proton is donated.
Analyse the structures of the three respective conjugate bases: the ethoxide ion, the phenoxide ion, and the ethanoate ion. Construct a detailed argument that explains how different electronic effects—namely the **inductive effect** and **resonance delocalisation**—stabilise the negative charge in each case. Your explanation should clearly link the degree of charge stabilisation in each conjugate base to the observed pKₐ value of its parent acid.