Separating Mixtures Flashcards
1
Q
What is filtration and what does it seperate?
A
- separates an insoluble solid from a liquid
- mixture passes through filter paper to leave filtrate and residue
2
Q
What is evaporation and what does it separate?
A
- separates soluble solid from a solution
- heat solution until solvent evaporates away
3
Q
What is distillation and what does it separate?
A
- separates solvent from solution
- heat solution until solvent evaporates, then it goes through a condenser until it condenses into liquid
4
Q
What is fractional distillation and what does it separate?
A
- separates two miscible liquids with different boiling points
- heat until liquid a reaches boiling point, it evaporates and rises, goes through a condenser and turns back into liquid form
5
Q
Define miscible
A
Liquids that mix
6
Q
Define immiscible
A
Liquids that don’t mix
7
Q
What does a separating funnel separate and how does it work?
A
- separates immiscible liquids
- higher density liquid sinks, funnel can be opened to let it run out
8
Q
What is chromatography and what does it separate?
A
- separates several solids all soluble in same solvent, e.g dyes
- dyes placed at base of paper, and placed in solvent
- as solvent moves up paper, it moves dyes at different rates depending on their speed in the solvent
- more soluble dyes move faster up paper
- less soluble dyes move slower up paper
9
Q
What is the mobile phase in chromatography?
A
The solvent
10
Q
What is the stationary phase in chromatography?
A
The paper
11
Q
How to calculate Rf value?
A
Distance moved by pigment
——‐-‐————————————————
Distance from pigment origin to solvent front
12
Q
What is recrystallisation?
A
A method of purifying a solid and removing both insoluble and soluble impurities
