SEPARATING TECHNIQUES Flashcards
Define miscible…
Two liquids that dissolve completely
Explain decantation
Mix the solid and the liquid, then once the heavy particles have settled at the bottom, carefully pour out the water/liquid without allowing the particles of the solute to leave.
Why do we use a pencil to draw the line on a chromatography paper?
Pencil is insoluble in water, therefore it won’t rise up with the solvent. Other inks can travel up the chromatograph and confound with getting accurate results.
Why do we use locating agents on chromatography paper?
It makes the position colourless samples visible
What is the Rf value?
Rf value is the retention factor, and it can be calculated by dividing the distance moved by the substance by the distance travelled by the solvent front.
What is a chromatogram?
It is the chromatography paper at the end of the experiment.
Why is chromatography biologically important?
It can be used to analyze biological molecules such as amino acids, sugars, and nucleotide bases.
When do we use a separating funnel? Which layer will be denser?
To separate two immiscible liquids. The bottom layer will be denser than the top one.
What’s a residue & a filtrate?
A residue is the leftover insoluble material left on the filter paper. The filtrate is the solvent or the liquid that has been separated from the insoluble material and has been left in the beaker or the flask.
