Topic 2- States Of Matter And Mixtures Flashcards
What are the three states of matter
Solid
Liquid
Gas
What are the Property’s of a solid
- Strong forces between particles that hold them in a fixed position in a lattice arrangement
- Particles don’t move from their positions so all solids keep a definite shape and volume
- The particles don’t have much energy
- Can only vibrate - the hotter a solid is the more they vibrate
What are the Property’s of liquids
- Some forces of attraction between the particles means they’re able to move past each other but they do tend to stick together
- Liquids don’t keep a definite shape but do keep the same volume
- more energy then a solid but less then a gas
- Constantly moving moving with random motion - the hotter it gets the more movement
What are the Property’s of a gas
- No force of attraction between the particles - free to move - move in straight lines and only interact when they collide
- Don’t keep a definite shape or volume and will always fill any container - when particles bounce off of a wall of a container they exert a pressure in the wall
- More energy then a solid and liquid
- Particles move constantly with random motion - the hotter a gas gets the faster it moves - pressure increases
What happens when a solid heats
It can eventually become a liquid
What happens when a liquid freezes
Becomes a solid
What happens when a liquid heats
Eventually Becomes a gas
How does a gas become a liquid
Condensing
What’s harder to reverse physical change or chemical change
Chemical change
What is a pure substance
A substance that is made up of a single element or compound
What’s a mixture
When you have more then one compound present, or different elements that aren’t all part of a single compound
Property’s of pure substances
Specific, sharp , melting and boiling points
Property’s of a mixture
Can melt over a range of temperatures
What’s Simple distillation used for
Separating liquid from a solution e.g. pure water from sea water
What are the Simple distillation (practical) steps using sea water as an example
- Pour your sample of sea water into the distillation flask
- Set up the apparatus. Connect the bottom of the condenser to a cold tap using rubber tubing. Run cold water through the condenser to keep it cool.
- Gradually heat the distillation flask . The part of the solution that has the lowest boiling point - in this case the water.
- The water vapour passes into the condenser where it cools and condenses(turns back into a liquid). It then flows into the beaker where it is collected.
- Eventually you’ll end with just salt in the flask.
What’s the problem with simple distillation
You can only use this to separate things with Very different boiling points because if you have a mixture of two liquids with similar boiling points you can get confused ( this is why fractional distillation exists)
When is fractional distillation needed
When you have a mixture of two liquids that need to be separated e.g. crude oil
How do you test for purity
Using melting points