Topic 2- States Of Matter & Mixtures 📄 Flashcards
What are the 5 methods for separating solutions?
- Filtration
- Evaporation
- Crystallisation
- Distillation
- Chromatography
How do identify a pure substance on a graph?
There is a horizontal line
How do identify an impure substance on a graph?
There is no horizontal line
—> The boiling and melting points range
What is the difference between a pure and impure substance?
Pure substances have set melting and boiling points whereas impure substances have a range of melting and boiling points
What is the definition of soluble?
Able to be dissolved in a solvent (especially water)
What is the definition of insoluble?
Incapable of being dissolved in a specific solvent
What is the definition of solvent?
The liquid in which the solute dissolves to form a solution
What is the definition of solute?
The solid (occasionally a gas) which dissolves into a solvent (liquid) in order to make a solution
What is the definition of solution?
A mixture made when a solute (usually a solid) dissolves into solvent (liquid)
What is the definition of concentrated?
Present in a high proportion to other relative substances; having had water or another diluting agent removed or reduced
What is the definition of dilute?
To make (a liquid) thinner or weaker by adding water or another solvent to it
What is the definition of saturated?
When no more solute can be dissolved in a solvent
What is chromatography?
A way to separate a mixture of soluble substances (eg. dyes, inks, colourings)
What are the 2 phases in chromatography?
- Stationary phase
- Mobile phase
What is the stationary phase in chromatography?
Paper
What is the mobile phase in chromatography?
Solvent (eg. Water)
What is a chromatogram?
The paper once the substances have separated
What does Rf stand for?
Retention Factor
How do you calculate the Rf value?
Distance travelled by solute
——————————————
Distance travelled by solvent
(Note: must be less than 1)
What is the difference between simple and fractional distillation?
Simple distillation can only separate 2 fractions and fractional distillation can separate multiple
What is the process of distilling crude oil?
- Crude oil is heated until it turns into a gas
- The vaporised crude oil travels into the fractioning column
- The fractioning column is cool at the top and hot at the bottom
- The fraction with the lowest boiling point condenses into a liquid first and is siphoned off.
What does ‘making water potable’ mean?
Making water safe to drink
Where does the UK get the majority of our drinking water from?
Rainfall
Where do countries with little rainfall get their drinking water from?
Desalination
What are the 3 stages of making water potable?
- Filtration
- Sedimentation ( microscopic, insoluble particles)
- Chlorination (kills microorganisms, like bacteria and fungi)
What are the 3 steps of making water potable?
- Filter substances that are insoluble through sand and gravel
- The large insoluble particles sink to the bottom and are clumped together
- Chlorine (or ozone or UV light) is added to water to kill bacteria
What are some disadvantages of desalination?
-Expensive
-Simple distillation
-Uses fossil fuels to heat up sea water constantly
Filtration
A way of separating a solvent and an insoluble solid
Fractional distillation
Used to separate individual liquids from a mixture
Simple distillation
Separates a solvent from a solution
Evaporation/ crystallisation
A way of separating soluble solutes from a liquid, due to different boiling points
Chromatography
A way to separate a mixture of soluble substances
