Chapter 20.7, Problem 20P

Interpretation Introduction

Interpretation:

The reason should be given for protonated pyrimidine $\left(\text{p}{K}_{\text{a}}=1.0\right)$ is more acidic than protonated pyridine $\left(\text{p}{K}_{\text{a}}=5.2\right)$.

Concept Introduction:

The role of $p{K}_{a}andpH$ value:

The acidic strength of a compound results in the formation of more hydrogen ions and less $\text{pH}$ value of the solution. The major factors that contribute to the acidic strength are $\text{p}{K}_{\text{a}}$ value, inductive effect and polarity. If the $\text{p}{K}_{\text{a}}$ value is more, then $\text{pH}$ value will be less and vice-versa. The value of $\text{pH}$ ranges from $1\text{to}14$. The $\text{pH}$ value less than $7$ indicates the formation of an acidic solution, whereas the $\text{pH}$ value more than $7$ results in the formation of a basic solution.