separating techniques Flashcards
(27 cards)
Something that CAN dissolve is described as being…
soluble
How much of something that can be dissolved is called…
solubility
Something that CANNOT be dissolved is described as being…
insoluble
A technique used to separate a solvent from a solution
distillation
The solid that will be dissolved, is the…
solute
The mixture of solute and solvent is called the…
solution
The liquid that the solute will be dissolved into is the…
solvent
what does filtration separate
insoluble solids from liquids
definition of pure
a substance made of 1type of element/compound
how to separate a liquid and dissolved solid -
evaporation
how to separate more than two liquids
distillation
how to separate two coloured liquids
chromatography
Chromatography is used to…
separate mixtures of coloured or non-coloured substances that are soluble in the same solvent
How does chromatography separate inks on paper?
-The water is drawn up by capillary action (attraction between water molecules and paper).
-When the solvent reaches the ink spots, they are dissolved and carried up the paper.
-The most soluble ink travels the furthest, while the less soluble inks stay closer to the bottom.
how to filter something
-filter out by using filter paper and a funnel
how to turn rock salt into pure salt
-filtration and evaporation
-step 1: grind rock salt mixture so it can filter easier
-step 2: add 50ml of water into the mixture and mix
-step 3: use a funnel and filter paper to filter (the liquid/salt solution goes through but the solid/rocks don’t)
-step 4: heat the salt solution in an evaporating basin, the water evaporates leaving pure salt crystals behind
When is distillation used as a separating technique?
when separating a liquid from a solution or a mixture that have different boiling points
explain how distillation works
-heating the mixture —> when you heat a liquid mixture, the particles start moving faster - breaking the force of attraction between the particles to form a gas. The liquid with the lower boiling point will then turn into gas first because the particles need less heat to break the intermolecular force between the particles.
-evaporation —> the liquid that boils first evaporates because the particles have enough kinetic energy to break the force between the particles
-condensation —> the gas is then cooled down in the condenser. As it cools, the gas particles lose energy therefore cannot break the bond, leading to bonds created. This leads to it condensing. The separated liquid is then collected in a new container
What is the name given for the pencil line?
base line
Why should we use pencil for the baseline rather than pen?
Pen ink would dissolve in the solvent and move up the paper, whilst pencil is insoluble so won’t interfere
What are some solvents commonly used in chromatography?
water, ethonal
What is the name of the resulting paper we end up with? (chromatography)
A chromatogram
what does the ‘mobile phase’ refer to
the molecules that can move
Which is the mobile phase in paper chromatography?
the solvent
