Write the Henderson Hasselbalch equation for acidic buffer

Answer

To write the Henderson-Hasselbalch equation for an acidic buffer, follow these steps:

### Step 1: Understand the Components
An acidic buffer is composed of a weak acid (HA) and its conjugate base (A⁻). The pH of the buffer solution depends on the concentration of the weak acid and its conjugate base.

### Step 2: Define the Acid Dissociation Constant (pKa)
The pKa is the negative logarithm of the acid dissociation constant (Ka) of the weak acid. It is a measure of the strength of the acid in solution.

### Step 3: Write the Henderson-Hasselbalch Equation
The Henderson-Hasselbalch equation relates the pH of the buffer solution to the pKa of the weak acid and the ratio of the concentrations of the conjugate base and the weak acid. The equation is given by:

\[ \text{pH} = \text{pKa} + \log\left(\frac{[\text{A}^-]}{[\text{HA}]}\right) \]

Where:
- pH = the acidity of the solution
- pKa = the negative logarithm of the acid dissociation constant (Ka)
- [A⁻] = concentration of the conjugate base
- [HA] = concentration of the weak acid

### Step 4: Interpret the Equation
This equation shows that the pH of the buffer solution can be adjusted by changing the ratio of the concentrations of the conjugate base to the weak acid. If the concentration of the conjugate base increases, the pH will increase, making the solution less acidic. Conversely, if the concentration of the weak acid increases, the pH will decrease, making the solution more acidic.

### Final Equation
Thus, the final form of the Henderson-Hasselbalch equation for an acidic buffer is:

\[ \text{pH} = \text{pKa} + \log\left(\frac{[\text{A}^-]}{[\text{HA}]}\right) \]

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