1. What is Depression in Freezing Point?

Definition: The Depression in Freezing Point describes why adding a solute to a solvent results in the lowering of the freezing point of the solvent.

Purpose: This calculator determines the freezing point depression based on relative vapour pressure lowering and other thermodynamic properties.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \Delta T_f \) — Depression in Freezing Point (Kelvin)
• \( RLVP \) — Relative Lowering of Vapour Pressure
• \( [R] \) — Universal gas constant (8.314 J/mol·K)
• \( T_{fp} \) — Solvent Freezing Point (Kelvin)
• \( \Delta H_{fusion} \) — Molar Enthalpy of Fusion (J/mol)

3. Importance of Freezing Point Depression

Details: Understanding freezing point depression is crucial in chemistry, cryobiology, and industrial applications like antifreeze formulation.

4. Using the Calculator

Tips: Enter the relative lowering of vapour pressure, solvent freezing point in Kelvin, and molar enthalpy of fusion. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is relative lowering of vapour pressure?
A: It's the ratio of the vapour pressure lowering to the vapour pressure of the pure solvent.

Q2: What are typical values for molar enthalpy of fusion?
A: For water it's about 6.01 kJ/mol, but varies for different substances.

Q3: Why does freezing point depression occur?
A: The solute disrupts the solvent's crystal lattice formation, requiring lower temperatures to freeze.

Q4: What are practical applications of this calculation?
A: Used in making antifreeze, cryopreservation, and studying colligative properties.

Q5: How accurate is this calculation?
A: It provides theoretical values; actual results may vary based on solution non-ideality.