Chapter 18 Separation techniques Flashcards
Pure products
Only contains the particles shown in its formula
Solvent
A substance that dissolves the solute
Solute
A substance that is dissolved in the solvent
Solution
Mixture of one or more solutes dissolved in a solvent.
Aqueous solution
When water is the solvent.
Solubility of a substance in water
amount of the solute that dissolves in 100g of water at 25 degrees Celsius
Saturated solution
When no more solute can be dissolved in the solution at that temperature
Relationship between temperature and solubility
As temperature increases, the solubility of a substance also increases.
What are the separationmethods used to separate a solid from a liquid
Filtration
Crystallization
Evaporation (removes solvent completely)
How do you separate two solids
find a solvent that dissolves only one of them
What is simple distillation
Separate solvent from a solution
Boiling then condensing the solvent
Fractional distillation
Separate liquids from each other
Use the difference in boiling points
Uses of paper chromatography
Separate substances from a mixture
Check if a substance is pure
Identify substances
How does the solvent go up the chromatogram
Capillary action
Why do substances travel at different speeds
Depends on the attraction of the substance to the paper and the solvent
The more soluble the substance is in a solvent, the faster it will travel, therefore travelling further
Rf value
retention factor
Rf formula
Distance from the origin to dot/Distance from origin to solvent front
What happens to melting and boiling point of a substance if it is impure
Melting point falls
Boiling point rises
What is filteration
A separation method that is used to separate an insoluble solid from a solution
What is crystalisation
A separation method used to obtain a solid from a solution
What is evaporation
A separation method used to remove all the solvent in order to obtain a solute.
steps of chromatography
1)create sample using pestal and mortar
2)decant liquid to collect sample
3)mark baseline using pencil
4)place sample on chromatography
5)place paper in solvent, baseline shouldn’t be completely dipped in solvent
6)wait for pigment to travel if colours should be known use locating agent (ninhydrant sulfate)
steps of distillation
1) sample in round bottom flask
2) connect delivery tube and connect condenser on to delivery tube
3) heat round bottom flask using bunsen burner
4) water will condense through condensation chamber and will form in conical flask
steps of titration
1) take acid in buret, alkali in conical flask, add indicator to flask containing aklaki. add drop of acid from the buret
2) keep stirring after putting drop
3) wait for colour change from pink to colourless then salt is formed
steps of fillteration
attach filter paper to funnel, put sample through filter paper, solids will get trapped in paper (residue) and water will pass (filtrate)
when to use a burette
if the amount needed is in decimal eg 25.0
when to use pipette
moving small amounts of liquid or when measuring and dispensing liquid in mL units
