Organic Chemistry
Phenol has a lower pKa than cyclohexanol because it is a weaker acid.
Phenol has a lower pKa than cyclohexanol because it has a more stable conjugate base.
Phenol has a lower pKa than cyclohexanol because its conjugate base is also an acid.
Phenol has a lower pKa than cyclohexanol because it can easily give up another proton.