4.0g of caustic soda is dissolved in 100 cc of solution. The normality of solution is

Options

A. 1
B. 0.1
C. 0.5
D. 4

Explanation

To find the normality of the solution, we can follow these steps:

### Step 1: Understand the Concept of Normality
Normality (N) is defined as the number of gram equivalents of solute per liter of solution.

### Step 2: Identify the Given Values
- Mass of caustic soda (NaOH) = 4.0 g
- Volume of solution = 100 cc = 0.1 L (since 1000 cc = 1 L)

### Step 3: Calculate the Molecular Weight of Caustic Soda (NaOH)
The molecular weight of NaOH can be calculated as follows:
- Sodium (Na) = 23 g/mol
- Oxygen (O) = 16 g/mol
- Hydrogen (H) = 1 g/mol

So, the molecular weight of NaOH = 23 + 16 + 1 = 40 g/mol.

### Step 4: Calculate the Number of Gram Equivalents
The number of gram equivalents can be calculated using the formula:
\[ \text{Number of gram equivalents} = \frac{\text{Weight of solute (g)}}{\text{Molecular weight of solute (g/mol)}} \]
Substituting the values:
\[ \text{Number of gram equivalents} = \frac{4.0 \, \text{g}}{40 \, \text{g/mol}} = 0.1 \, \text{equivalents} \]

### Step 5: Calculate the Normality of the Solution
Using the formula for normality:
\[ \text{Normality (N)} = \frac{\text{Number of gram equivalents}}{\text{Volume of solution in liters}} \]
Substituting the values:
\[ \text{Normality (N)} = \frac{0.1 \, \text{equivalents}}{0.1 \, \text{L}} = 1 \, \text{N} \]

### Final Answer
The normality of the solution is **1 N**.

---