Principle
The freezing point of a solution is lower than that of the pure solvent. The depression of the freezing point can be determined experimentally using a suitable apparatus (cryoscopy). If the cryoscopy constants of the solvent are known, the molecular mass of the substance dissolved can be determined.
Benefits
- All relevant measured variables at a glance
- Experimentation made easy by intuitive operation
- With detailed experiment guide
Tasks
- Determine the size of freezing point depression after dissolving a strong electrolyte (NaCl) in water.
- Determine the number of ions into which the electrolyte dissociates.
- Determine the molar mass of a non-electrolyte (hydroquinone) from the value of freezing point depression.
Learning objectives
- Raoult's law
- Cryoscopic constant
- Chemical potential
- Gibbs-Helmholtz equation
- Concentration ratio
- Degree of dissociation
- Van't Hoff factor
Necessary accessories
- Precision balance 620g/0.001g