Chromatography Flashcards
Use of paper chromatography
to separate mixtures, especially dyes and pigments
How does paper chromatography work
Solvent (mobile phase) is placed on paper (stationary phase)and is drawn up by capillary action.
-different substances will be soluble to water and attracting to the paper =absorb onto surface and desorb into a solvent at different rates due to their nature
How does thin layer chromatography work
Solvent (mobile phase) is placed on layer of silica gel (stationary phase)
some particles stick better to gel= lag depending on solubility and charge and their interaction with matrix
What is retardation factor
ratio between distance travelled by sample and distance travelled by solvent
How does gas chromatography work
Inert gas (mobile phase) injected into long thing tube of silica gel/alumina
What is Rt
retention time
time taken for results in a value
How does high performance liquid chromatography work
Liquid (mobile phase) solid silica material (stationary phase)
What is HPLC used for
Large organic molecules + thermally unstable
What does desorb mean?
Action of substance moving from stationary to mobile phase
What does absorb mean
Action of substance attracting to surface of a material
What is mobile phase
Phase carrying solutes/dissolves mixture
What is stationary phase
fixedin place during chromatography where solutes absorb
What is analyte?
substance separates from process
What is an element?
substances composed of only one type of atom
What is a compound?
composed of more than 1 type of atom strongly bonded together
What is dif. between homogenous and heterogenous mixtures
Hetero-variable copositions+properties
Homo-same distribution of components + properties
What is an alloy?
metal mixed with other metals
What is a polymer?
Large molecules made of multiple units
What are Ceramics
Inorganic, non-metallic solids formed from a mixture of metals and non-metals
Define composite
Material made from 2 or more materials
What are the separation techniques used for separating?
-particle size
-boiling points
-density
-magnetism and electrostatic attraction
-absorbency
Particle size separation techniques
-sieving
-filtration
Density separation techniques
-sedimentation
-decantation
-centrifuge
-separation funnels
Boiling point separation techniques
-evaporation
-distillation
Electric charge separation techniques
-electrostatic separation
-chromatography
