Calculate the pH of following solutions.
`0.1N HCl`

Answer

To calculate the pH of a 0.1N HCl solution, follow these steps:

### Step 1: Understand the nature of HCl
HCl is a strong acid, which means it completely dissociates in water. Therefore, when we have a 0.1N (normal) solution of HCl, it will ionize completely to produce hydrogen ions (H⁺) and chloride ions (Cl⁻).

### Step 2: Write the dissociation equation
The dissociation of HCl in water can be represented as:
\[ \text{HCl} (aq) \rightarrow \text{H}^+ (aq) + \text{Cl}^- (aq) \]

### Step 3: Determine the concentration of H⁺ ions
Since HCl is a strong acid and completely dissociates, the concentration of H⁺ ions in the solution will be equal to the concentration of HCl. Therefore, for a 0.1N HCl solution:
\[ [\text{H}^+] = 0.1 \, \text{M} \]

### Step 4: Calculate the pH
The pH of a solution is calculated using the formula:
\[ \text{pH} = -\log [\text{H}^+] \]
Substituting the concentration of H⁺ ions:
\[ \text{pH} = -\log (0.1) \]

### Step 5: Simplify the logarithm
The logarithm of 0.1 can be simplified:
\[ \log (0.1) = \log (10^{-1}) = -1 \]
Thus:
\[ \text{pH} = -(-1) = 1 \]

### Final Answer
The pH of the 0.1N HCl solution is **1**.

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