The pH value of `N//10` NaOH is

Options

A. 7
B. 10
C. 12
D. 13

Explanation

To find the pH value of a `N/10` NaOH solution, we can follow these steps:

### Step 1: Determine the concentration of NaOH
Given that the normality of NaOH is `N/10`, we can convert this to molarity. For NaOH, which is a strong base, the normality is equal to the molarity since it provides one hydroxide ion (OH⁻) per formula unit. Therefore, the molarity (M) of NaOH is:
\[ \text{Molarity} = \frac{N}{10} = \frac{1}{10} = 0.1 \, \text{M} \]

### Step 2: Find the concentration of hydroxide ions (OH⁻)
Since NaOH is a strong base, it completely dissociates in solution. Therefore, the concentration of hydroxide ions (OH⁻) is equal to the molarity of NaOH:
\[ [\text{OH}^-] = 0.1 \, \text{M} \]

### Step 3: Calculate pOH
To find the pOH of the solution, we use the formula:
\[ \text{pOH} = -\log [\text{OH}^-] \]
Substituting the concentration of OH⁻:
\[ \text{pOH} = -\log(0.1) = -\log(10^{-1}) = 1 \]

### Step 4: Calculate pH
We know that:
\[ \text{pH} + \text{pOH} = 14 \]
Now, substituting the value of pOH:
\[ \text{pH} = 14 - \text{pOH} = 14 - 1 = 13 \]

### Conclusion
The pH value of `N/10` NaOH is:
\[ \text{pH} = 13 \]

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