P1C2 - Methods: sep + pur

Question 1

What is a mixture?

Answer 1

Two or more elements not chemically bonded together

Question 2

What are some separation techniques?

Answer 2

Filtration
Crystallisation
Chromatography

Question 3

How do you calculate Rf value ?

Answer 3

Distance travelled by substance /
Distance travelled by solvent

Question 4

What are the steps to crystallisation?

Answer 4

1. Heat the solution in an evaporating basin above a beaker of water.
   The ‘water bath’ ensures gentle heating.
2. Let the solution cool and allow more water to evaporate.
3. As water evaporates, the solution will become more concentrated and the salt will begin to crystallise.

Question 5

Why is filtration used?

Answer 5

To separate an undissolved solid from a liquid.