Identify the correct order of acidic strength for the following compounds in aqueous solution: (i) (ii) (iii)

Step-by-step solution

The acidic strength of the given compounds depends on the stability of their conjugate bases and their predominant tautomeric forms in aqueous solution. Compound (i) is phenol. It has a pK_a of approximately 10.0 . Its conjugate base, the phenoxide ion, is stabilized by resonance over the carbon atoms of the benzene ring. Compound (ii) is 2-hydroxypyridine. In aqueous solution, it exists predominantly as its amide-like tautomer, 2-pyridone. The neutral 2-pyridone molecule is highly stabilized, which increases the e