P1C2 - Methods: sep + pur Flashcards
1
Q
What is a mixture?
A
Two or more elements not chemically bonded together
2
Q
What are some separation techniques?
A
Filtration
Crystallisation
Chromatography
3
Q
How do you calculate Rf value ?
A
Distance travelled by substance /
Distance travelled by solvent
4
Q
What are the steps to crystallisation?
A
- Heat the solution in an evaporating basin above a beaker of water.
The ‘water bath’ ensures gentle heating. - Let the solution cool and allow more water to evaporate.
- As water evaporates, the solution will become more concentrated and the salt will begin to crystallise.
5
Q
Why is filtration used?
A
To separate an undissolved solid from a liquid.