Lab Analyticals Flashcards
Filtration
used to separate a liquid from a solid
distillation
used to separate liquids from each other, must have different BP by more than 5 degrees Celsius
chromatography
used to separate materials that have different abilities to adhere/adsorb to a solid surface
the mixture to separate is dissolved in a mobile phase
Stationery phase affinity
the greater the affinity a component has for the stationery phase, the greater its retention time in the column and the longer it remains in the column.
mobile phase affinity
the faster it moves
crystallization
- used to purify a compound from trace impurities
- based on the differences in solubility of the component mixtures
- dependent on whether the solvent is hot or cold and the component to be dissolved must be soluble when the solvent is hot and insoluble when the solvent is cold
Beer- Lamberts law
A = ξ x L x C
what properties does it relate to?
it relates the absorption of light to the concentration of the material through which light is travelling.
- absorption is ∝ concentration
when to use centrifugation
solid partiles in a liquid median
when to use precipitation
when ions are involved (present in solution)
When to use distillation
different boiling points
When to use chromatography?
different absorptions
when to use crystallization?
different solubility’s
