Chapter 19, Problem 19.18P

Interpretation Introduction

Interpretation: The explanation corresponding to the given statement that the $\text{p}{K}_{\text{a}}$ of phenol A, one of the naturally occurring phenols called urushiols isolated from poison ivy, should be higher or lower than the $\text{p}{K}_{\text{a}}$ of phenol $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\text{OH,}\text{p}{K}_{\text{a}}=10\right)$ is to be stated.

Concept introduction: The $\text{p}{K}_{\text{a}}$ value is inversely related to the acidic strength of the compound. The major factors that contribute to the acidic strength are $\text{s}$ character, inductive effect and polarity. The high percentage of $\text{s}$ character increases the acidity. There are two types of inductive effects named as positive or electron releasing and negative or electron withdrawing inductive effect. Positive inductive effect lowers the acidic strength of the compounds, whereas negative inductive effect increases the acidic strength of the compounds.