Give possible explanation for the following.
(a) Ortho-nitrophenol is more acidic than ortho-methoxyphenol.
(b) Alcohols are easily protonated in comparision to phenols.
(c) The relative ease of dehydration of alcohols is : tertiary `gt` secondary `gt` primary.

Explanation

(a) Nitro `(- NO_(2))` group is an electron withdrawing group due to `- I` and `- R` effects. Under its influences, `O-H` bond is under strain and release of `H^(+)` becomes easy. The methoxy `(-OCH_(3))` group on the other hand is an electron releasing group because of `+ I` and `+ R` effects. Due to its presence, the electron density on the ring as well as on the `O-H` bond increases. This makes the release of `H^(+)` ion difficult.

(b) In alcohol, the lone electron pair on oxygen is available for protonation. However, it is less available in phenol because of its conjugation with the pi-electrons of the ring.
(c) This attributed to the relative stabilities of the carbocations in the order :
tertiary `gt` secondary `gt` primary. For more details, consult section 8