Calculate pH solution:
0.1 M HCl

Answer

To calculate the pH of a 0.1 M HCl solution, we can follow these steps:

### Step 1: Understand the concept of pH
pH is defined as the negative logarithm (base 10) of the concentration of hydrogen ions (H⁺) in a solution. The formula is given by:
\[ \text{pH} = -\log[H^+] \]

### Step 2: Identify the concentration of H⁺ ions
In the case of HCl, which is a strong acid, it completely dissociates in water. Therefore, the concentration of H⁺ ions in a 0.1 M HCl solution is:
\[ [H^+] = 0.1 \, \text{M} \]

### Step 3: Substitute the concentration into the pH formula
Now, we can substitute the concentration of H⁺ ions into the pH formula:
\[ \text{pH} = -\log(0.1) \]

### Step 4: Calculate the logarithm
To calculate \(-\log(0.1)\), we can express 0.1 as:
\[ 0.1 = \frac{1}{10} \]
Thus, we can rewrite the logarithm:
\[ -\log(0.1) = -\log\left(\frac{1}{10}\right) = -(-1) \cdot \log(10) = 1 \]

### Step 5: Conclusion
Therefore, the pH of the 0.1 M HCl solution is:
\[ \text{pH} = 1 \]

### Summary of Steps:
1. Understand pH definition.
2. Identify concentration of H⁺ ions in HCl.
3. Substitute into pH formula.
4. Calculate the logarithm.
5. State the final pH value.