Out of o-nitrophenol and o-cresol which is more acidic ?

Explanation

The acidic character of alcohols is due to the polar nature of `O-H` bond. Higher the polarity of O-H bond, more will be the acidic strength. Due to -I and -R effect of nitro group, electron density decreases in the O-H bond of o-nitrophenol and thus polarity increases.

Whereas due to +I effect of `-CH_(3)` group, electron density increases in the O-H bond of o-cresol. Thus, O-H of o-nitrophenol is weaker than O-H bond of o-cresol.