Consider the following compounds: I. Cyclohexanol II. Phenol III. p -Nitrophenol IV. p -Methoxyphenol The correct decreasing order of their ease of protonation is:

Step-by-step solution

The ease of protonation (basicity) depends on the availability of the lone pair of electrons on the oxygen atom. In cyclohexanol (I), the oxygen atom is attached to an sp^3 hybridized carbon, and its lone pairs are fully localized. This makes it the most electron-rich and easiest to protonate among the given compounds. In phenol (II), p -nitrophenol (III), and p -methoxyphenol (IV), the oxygen atom is attached to an aromatic ring, and its lone pair is delocalized into the ring via resonance, making them less basic