The normally of `4%` (wt/vol).`NaOH` is:

Options

A. `0.1`
B. `1.0`
C. `0.05`
D. `0.01`

Explanation

To find the normality of a 4% (wt/vol) NaOH solution, we can follow these steps:

### Step 1: Understand the given percentage
The term "4% (wt/vol)" means that there are 4 grams of NaOH in 100 mL of solution.

### Step 2: Calculate the weight of NaOH in 1 L of solution
Since normality is typically expressed per liter (L), we need to convert the volume from mL to L:
- 1000 mL = 1 L
- Therefore, in 1 L of solution, there would be \( 4 \, \text{g} \times \frac{1000 \, \text{mL}}{100 \, \text{mL}} = 40 \, \text{g} \) of NaOH.

### Step 3: Determine the equivalent weight of NaOH
The equivalent weight of NaOH can be calculated using the formula:
\[ \text{Equivalent weight} = \frac{\text{Molecular weight}}{\text{n}} \]
Where:
- The molecular weight of NaOH is approximately 40 g/mol.
- Since NaOH produces one hydroxide ion (OH⁻) per molecule, the number of equivalents (n) is 1.

Thus, the equivalent weight of NaOH is:
\[ \text{Equivalent weight} = \frac{40 \, \text{g/mol}}{1} = 40 \, \text{g/equiv} \]

### Step 4: Calculate the normality
Normality (N) is calculated using the formula:
\[ N = \frac{\text{Weight of solute (g)}}{\text{Equivalent weight (g/equiv)} \times \text{Volume of solution (L)}} \]
Substituting the values we have:
\[ N = \frac{40 \, \text{g}}{40 \, \text{g/equiv} \times 1 \, \text{L}} = 1 \, \text{N} \]

### Conclusion
The normality of the 4% (wt/vol) NaOH solution is **1 N**.

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