Chapter 1, Problem 18P

Interpretation Introduction

(a)

Interpretation:

The $\text{pH}$ of the buffer is to be determined.

Concept introduction:

Henderson and Haselbalch equation is used to find the $\text{pH}$. The expression is as given below,

$\text{pH}=\text{p}{K}_{\text{a}}+\log \frac{\left[{\text{A}}^{-}\right]}{\left[\text{HA}\right]}$ ...... (1)

Where,

• $\left[{\text{A}}^{-}\right]$ is the concentration of ${\text{A}}^{-}$ ions.
• $\left[\text{HA}\right]$ is the concentration of hypothetical acid $\text{HA}$ .
• $\text{p}{K}_{\text{a}}$ is dissociation constant.

Interpretation Introduction

(b)

Interpretation:

The ${\text{pK}}_{\text{a}}$ of the buffer solution is to be determined.

Concept introduction:

Henderson and Haselbalch equation is used to find the ${\text{pK}}_{\text{a}}$ value. The expression is as given below,

$\text{pH}=\text{p}{K}_{\text{a}}+\log \frac{\left[{\text{A}}^{-}\right]}{\left[\text{HA}\right]}$ ...... (1)

Where,

• $\left[{\text{A}}^{-}\right]$ is the concentration of ${\text{A}}^{-}$ ions.
• $\left[\text{HA}\right]$ is the concentration of hypothetical acid $\text{HA}$ .
• $\text{p}{K}_{\text{a}}$ is dissociation constant.

Interpretation Introduction

(c)

Interpretation:

The ratio of $\left[{\text{A}}^{\text{-}}\right]$ to $\left[\text{HA}\right]$ is to be determined.

Concept introduction:

Henderson and Haselbalch equation is used to find the $\left[{\text{A}}^{\text{-}}\right]$ to $\left[\text{HA}\right]$ ratio value. The expression is as given below,

$\text{pH}=\text{p}{K}_{\text{a}}+\log \frac{\left[{\text{A}}^{-}\right]}{\left[\text{HA}\right]}$ ...... (1)

Where,

• $\left[{\text{A}}^{-}\right]$ is the concentration of ${\text{A}}^{-}$ ions.
• $\left[\text{HA}\right]$ is the concentration of hypothetical acid $\text{HA}$ .
• $\text{p}{K}_{\text{a}}$ is dissociation constant.