Physical changes Flashcards
What are the 3 states of matter?
- Solid
- Liquid
- Gas
Particles arrangement for Solids?
- Very close together
- Regular ordered arrangement
- Don’t move/ can only vibrate
Particles arrangement for Liquids?
- Particles are quite close together
- Radom arrangement
- Move fairly freely
Particles arrangement for Liquids?
- Particles wide apart
- Radom arrangement
- Move freely
What is the name of change state when a SOLID become LIQUID?
Melting
What is the name of change state when a LIQUID become GAS?
Evaporating
What is the name of change state when a LIQUID become a SOLID?
Freezing
What is the name of change state when a GAS become LIQUID?
Condensing
What is the name of change state when a SOLID become GAS?
Sublimation
What is the name of change state when a GAS become SOLID?
Deposition
When do substances change state?
When their THERMAL ENERGY changes.
A solid can be changed into a liquid by increasing its thermal energy.
Similarly, thermal energy must be decreased to cause a gas to change into a liquid.
What is the MELTING POINT?
Melting point is the temperature at which a solid changes into a liquid
What is the BOILING POINT?
The Boiling point is the temperature at which a liquid changes into a gas.
Note: PURE substances have a specific melting/boiling points
While MIXTURES melt and boil over a range of temperatures.
What is a PURE substance?
A pure substance contains one type of chemcial substance only.
What are MIXTURES?
Mixtures are materials that contain 2 or more chemical substances mixed together.
What are the 2 types of Mixtures?
There are 2 types of Mixtures:
- HOMOGENOUS MIXTURE- where the particles of the substances are mixed together and there is no clumping.
- HETEROGENEOUS MIXTURE- where large clumps of the substances are mixed together
What are SOLUTIONS?
Solutions are homogenous mixtures.
Solution = solute dissolving in a solvent
e.g. Salty water
What is a SOLUTE?
A substance that dissolves in a liquid.
What is the SOLVENT?
The liquid that dissolves the solutes
What is the FILTRATE?
The solid left behind on the filter paper after filtration.
What is the RESIDUE?
The liquid collected in the conical flask after filtration
What is SOLUBLE?
The solid that dissolves in the solvent.
e.g. salt, sugar
What is INSOLUBLE?
A substance that does not dissolve in a solvent.
e.g. sand
What are the SEPARATING TECHNIQUES>
- FILTRATION- can be used to separate a mixture where the solid in insoluble. The insoluble solid is the residue that remains in the filter paper.
- CRYSTALLISATION/ Evaporation- can be used to separate a solute from the solution. Heat the solution until crystals start to form. Once cooled, filtration can be sued to obtain the crystals from the remaining solution.
- PAPER CHROMATOGRAPHY- can be used to separate a mixture of soluble substances (e.g. coloured inks)
- Simple DISTILLATION- can be used to separate the components of a solution with different boiling points.
How does Paper Chromatography work?
A spot that travels the furthest up the paper is very soluble, whereas a spot that stays on the pencil line is insoluble in the solvent.
What are the practical steps to take with Paper Chromatography?
- Draw base line in pencil
- Spot each colour in turn
- Label the spots
- Add water in the beaker
- Fold paper round splint and paperclip
- Place Chromatogram in beaker
- Remove Chromatogram and draw the solvent front in pencil
What are the different stages of DISTILLATION
- The solvent start to boil
- The solvent evaporates
- The solvent vapour travels into the condenser
- The solvent vapour is cooled by the condenser
- The liquid solvent flows from the condenser into the beaker.
At what temperature, water change state from liquid to gas?
100C
At what temperature water change state from liquid to solid?
0C
