5. Separation and Identification of the components of mixtures Flashcards
What is a solute?
dissolved substance in a solution
What is a solvent
the substance in which the solute is dissolved
What is a solution?
Solute dissoved in a solvent
What is a phase?
The physical form in which a substance is present; common phases include solid, liquid, gas and aqueous solution, as well as other phases
What is polarity?
Localised imbalances in electric charges within a molecule resulting in negatively charged end and positively charged end.
What is the like dissolves like rule?
The like dissolves like rule states that polar solutes are more soluble in polar solvents, whereas nonpolar solutes are more soluble in non polar solvents.
What is the mobile phase?
the mixture to be analysed in the chromatography process
What is the stationary phase?
a material with a high surface area, used in the chromatography process.
Eg. paper chromatography, the stationary phase is water.
What is chromatography?
a technique for the separation of a mixture by passing it in a solution (mobile phase_ over a stationary phase; separation occurs as components move at different rates
What is adsorption?
the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface.
What is desorption?
the opposite of adsorption, where molecules are released from the surface of other particles.
What is the Rf value?
In chromatography, the retardation factor, the ratio of the distance travelled by the solute to the distance travelled by the solvent.
distance moved by solute Rf = ---------------------------------------
