chap 4 Flashcards
What are the parts used in distillation and why are it’s purpose?
Boiling chips - to ensure smooth boiling
Condenser - to cool and condense the hot vapour into liquid.
Thermometer: to measure the boiling point of the liquid in the distillation flask
Where is the water inlet and the water outlet located on the condenser ( distillation ), and how does it work
water inlet bottom
water outlet top,
both allows a cool surface to be maintained in the condenser for condensation
As the condenser slopes downwards, cold water must enter the condenser from the bottom outlet to ensure that the condenser is fully filled with water.
What is the purpose of filtration
to separate substances of different particle sizes
what is the purpose of using evaporation as a separation technique .
to obtain dissolved solid (solute) from a liquid (solvent)
what is the purpose of distillation.
to separate substances with different boiling points through boiling and condensation.
what is the purpose of paper chromatography .
to separate small amounts of substances from mixtures based on the different solubilities of the components in a particular solvent.
how does filtration work
solid particles larger than the pore size of the filter paper will be trapped as residue while particles small enough to pass through the pores of the filter paper will end up as filtrate
Why do we
1. use graphite to draw the starting line
2. ensure that the sample spot is above the solvent level
3. cover the bottle
in chromatography
- graphite is insoluble in the solvent, hence it will not lead to an inaccurate chromatogram
- to prevent the sample from dissolving in the solvent before it is carried up the chromatography paper
- the lid stops the solvent from evaporating as it rises up the paper.
What are the applications of filtration?
- separating a mixture of chalk and water
- separating tea leaves from tea
what re the applications of chromatography
-analysing food dyes to ensure that only permitted colourings are used
- detecting trace levels of drugs in urine samples
- to separate the different coloured components that make up black ink
What are the applications of distillation?
- making perfumes
- obtaining pure water from salt solution
- making food flavourings
what are the applications of evaporation
-obtaining salt from seawater
-drying food for preservation