Fundamentals
What is Thermodynamics?
Thermoynamics is the science of interaction between material and matter:
It describes how adding/removing heat or changing the chemical environment (adding/removing a solvent) changes the properties of a mixture.
Example:
Adding heat to water will evaporate it
Adding water to salt will dissolve it
Applications:
Separation of mixtures is generally based on one of the two following phenomena:
- Evaporation: heating a mixture will make that the individual components will evaporate to a different degree depending on their respective volatilities
- Solvation: Adding a solvent to a mixture will attract the compounds that have the highest affinity for the solvent towards this product
Activity:
The reactivity of a compound depends on temperature, but also on its surrounding
Electrolytes are species that tend to loose or gain electrons when dissolved into a solvent (typically with a large dielectric constant, as water).
Consequences of this phenomenon are large:
- Strong solubility in the solvent
- Strong reactivity of the compound (formation of chemical complexes)
- The activity (tendency to react) of the compound is strongly affected (e.g. corrosion…)
Definitions are often very confusing. This document aims at clarifying some important concepts:
