1. What is Molality?

Molality (m) is a measure of the concentration of a solute in a solution, defined as the number of moles of solute per kilogram of solvent. Unlike molarity, molality is not affected by temperature changes because it's based on mass rather than volume.

2. How to Calculate Molality

The formula for calculating molality is:

Where:

• \( m \) — Molality (mol/kg)
• \( n_{\text{solute}} \) — Amount of solute in moles (mol)
• \( kg_{\text{solvent}} \) — Mass of solvent in kilograms (kg)

Explanation: To calculate molality, divide the number of moles of solute by the mass of solvent in kilograms.

3. Importance of Molality

Details: Molality is particularly useful in:

• Colligative property calculations (boiling point elevation, freezing point depression)
• Experiments involving temperature changes
• Solutions where volume might change with temperature

4. Using the Calculator

Tips:

• Enter the amount of solute in moles
• Enter the mass of solvent in kilograms
• All values must be positive numbers
• The calculator will compute molality in mol/kg

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between molality and molarity?
A: Molality uses mass of solvent (mol/kg), while molarity uses volume of solution (mol/L). Molality is temperature-independent.

Q2: When should I use molality instead of molarity?
A: Use molality when working with temperature-sensitive experiments or colligative properties.

Q3: Can molality be used for any solvent?
A: Yes, molality can be used with any solvent as long as you know the mass of the solvent.

Q4: What are typical molality values?
A: Common solutions range from 0.1 to 6 mol/kg, but this depends on the solubility of the solute.

Q5: How precise should my measurements be?
A: For most applications, 3-4 significant figures are sufficient, but research applications may require higher precision.