Calculate the pH value of 0.001 N `HNO_(3)` solution.

Answer

To calculate the pH value of a 0.001 N HNO₃ solution, follow these steps:

### Step 1: Identify the nature of HNO₃
HNO₃ (Nitric acid) is a strong monobasic acid. This means it completely dissociates in water to produce hydrogen ions (H⁺) and nitrate ions (NO₃⁻).

### Step 2: Determine the concentration of H⁺ ions
Since HNO₃ is a strong acid, the concentration of H⁺ ions will be equal to the normality of the solution. Therefore, for a 0.001 N HNO₃ solution:
\[ [H^+] = 0.001 \, \text{N} = 0.001 \, \text{mol/L} \]

### Step 3: Use the pH formula
The pH of a solution is calculated using the formula:
\[ \text{pH} = -\log[H^+] \]

### Step 4: Substitute the concentration into the pH formula
Substituting the concentration of H⁺ ions into the pH formula gives:
\[ \text{pH} = -\log(0.001) \]

### Step 5: Simplify the logarithm
We can express 0.001 as \( 10^{-3} \):
\[ \text{pH} = -\log(10^{-3}) \]

### Step 6: Calculate the pH
Using the properties of logarithms:
\[ \text{pH} = -(-3) = 3 \]

### Final Answer
Thus, the pH value of the 0.001 N HNO₃ solution is:
\[ \text{pH} = 3 \]

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