Chapter 17.3, Problem 3CP

Interpretation Introduction

Interpretation:

The $\text{pH}$ of the solutionafter addition of $\text{NaOH}$ into the $\text{HF}$ solution is to be determined, with given concentration and volume.

Concept introduction:

Acid–base titration is a technique to analyze the unknown concentration of the acid or base with the help of the known concentration of the acid and base.

The equivalence point is the point in an acid–base titration in a chemical reaction where number of moles of the titrant and the unknown concentration of the analyte are equal. It is used to identify the unknown concentration of the analyte.

In strong acid–base titration, the pH of the solution is neutral (i.e. pH = 7) at equivalence point.

In weak acid–strong base titration, the pH of the solution is not neutral (pH> 7) at equivalence point.

In strong acid–weak base titration, the pH of the solution is not neutral (pH < 7) at equivalence point.

The number of moles of the molecule are calculated as:

$\text{Concentration}=\frac{\text{Moles}}{\text{Volume}}$.

The number of millimoles of a molecule are calculated as:

$\text{Millimoles of NaOH}=\text{Concentration of NaOH}\times \text{Volume of NaOH}$

For acidic buffer, the value of $\text{pH}$ is calculated using the expression as:

$\text{pH}={\text{pK}}_{\text{a}}+\log \frac{\left[\text{Conjugate}\text{Base}\right]}{\left[\text{Weak}\text{Acid}\right]}$.