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Cryoscopic Constant given Molar Enthalpy of Fusion Calculator

Cryoscopic Constant Formula:

\[ k_f = \frac{[R] \times T_{fp}^2 \times M_{solvent}}{1000 \times \Delta H_{fusion}} \]

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g/mol
J/mol

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1. What is Cryoscopic Constant?

Definition: The Cryoscopic Constant (kf) is the freezing point depression constant that describes how much the freezing point of a solvent decreases when a solute is added.

Purpose: It's used in chemistry to determine molecular weights of solutes and to study colligative properties of solutions.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ k_f = \frac{[R] \times T_{fp}^2 \times M_{solvent}}{1000 \times \Delta H_{fusion}} \]

Where:

Explanation: The formula relates the cryoscopic constant to fundamental thermodynamic properties of the solvent.

3. Importance of Cryoscopic Constant

Details: This constant is essential for determining molecular weights of unknown compounds and understanding solution behavior in various chemical and biological systems.

4. Using the Calculator

Tips: Enter the solvent's freezing point in Kelvin, molar mass in g/mol, and molar enthalpy of fusion in J/mol. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for cryoscopic constants?
A: Common values range from 1.5-5 K·kg/mol (water: 1.86, benzene: 5.12, camphor: 40).

Q2: Why is the universal gas constant in the formula?
A: The cryoscopic constant derivation comes from thermodynamic principles where [R] appears naturally.

Q3: What units should I use for molar mass?
A: The calculator expects grams per mole (g/mol) as input, but converts internally to kg/mol for the calculation.

Q4: How accurate is this calculation?
A: It provides theoretical values assuming ideal solution behavior. Real solutions may show deviations.

Q5: Can I use this for any solvent?
A: Yes, as long as you have accurate values for the required parameters.

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