Of the following terms used for denoting concentration of a solution the one which does not get affected by temperature is :

Options

A. Molarity
B. Molality
C. Normality
D. Formality

Explanation

To solve the question regarding which concentration term does not get affected by temperature, we will analyze each of the given terms: molarity, molality, normality, and formality.

### Step-by-Step Solution:

1. **Understanding Molarity**:
- Molarity (M) is defined as the number of moles of solute per liter of solution.
- Formula: \( M = \frac{\text{moles of solute}}{\text{volume of solution in liters}} \)
- **Effect of Temperature**: Since the volume of the solution can change with temperature (due to thermal expansion), molarity is affected by temperature.

2. **Understanding Molality**:
- Molality (m) is defined as the number of moles of solute per kilogram of solvent.
- Formula: \( m = \frac{\text{moles of solute}}{\text{mass of solvent in kg}} \)
- **Effect of Temperature**: The mass of the solvent does not change with temperature, so molality is independent of temperature.

3. **Understanding Normality**:
- Normality (N) is defined as the number of gram equivalents of solute per liter of solution.
- Formula: \( N = \frac{\text{gram equivalents of solute}}{\text{volume of solution in liters}} \)
- **Effect of Temperature**: Similar to molarity, normality is also affected by temperature due to changes in volume.

4. **Understanding Formality**:
- Formality (F) is defined as the number of gram formula mass of solute per liter of solution.
- Formula: \( F = \frac{\text{gram formula mass of solute}}{\text{volume of solution in liters}} \)
- **Effect of Temperature**: Like molarity and normality, formality is also affected by temperature.

5. **Conclusion**:
- Among the four terms, only **molality** is independent of temperature because it is based on the mass of the solvent, which does not change with temperature.

### Final Answer:
The concentration term that does not get affected by temperature is **molality**.