C1-C2 STATES OF MATTER AND SEPARATING SUBSTANCES Flashcards
Particle
The ting pieces that all matter is made from
Aron
The smallest independent particle everything is made of atoms
Molecule
A particle made from two or more atoms bonded together
States of matter
Whether a substance is solid , liquid or gas
Particle model
A theory ghat uses the idea is particles to explain the differences between solids, liquids or gases
Solid
Particle arrangement : regular pattern, touching each other
Particle movement : moving around
Liquid
Particle arrangement: random , touching each other
Particle movement : moving around
Gas
Particle arrangement: random
Particle movement: moving quickly
State changes
Solid to liquid=melting Liquid to solid=freezing Liquid to gas=evaporating it boiling Gas to liquid=condensation Solid to gas=sublimation Gas to solid=deposition
Heating curbs for a pure substance
Temperature rises as you heat a solid, levels out as it melts, continues rising once fully liquid, levels out whilst boiling and rises again one fully gas
Element
A substance made from only one type of atom
Compound
A substance made from two or more different elements bonded together
Mixture
A substance made of two of more substances (elements of compounds) mixed but not bonded together
Melting point of mixtures
Mixtures do not melt at a fixed temperature but melt gradually over a range of temperatures
Heating curves of mixtures
The flat sections of the heating curves of a pure substances are sloped for a mixture
Dissolve
When a substance mixes with a liquid by breaking down into individual particles (atoms or molecules)
Soluble
When a substance can be dissolved by a liquid
Insoluble
When a substance can’t be dissolved by a liquid
Filtration
A method of separating a mixture of a liquid and an insoluble solid by passing it through a filter paper
Residue
The solid that gets left behind I’m the filter paper
Filtrate
The liquid that passes through the filter paper
How filtration works
The filter paper contains many tiny holes
The water molecules are small enough to pass through the holes, the solid particles are too big and get trapped
Solution
A mixture of a solute dissolved in a solvent
Solvent
A liquid ghat has dissolved a substance , for example water
Solute
A solid that has been dissolved , for example salt
Crystallisation
A method of collecting the dissolved solid from a solution by beating it so that the solvent evaporated away
Risk of crystallisation
As the solvent boils away, the hot solution can split, so you should wear safety Google’s to protect your eyes
Paper chromatography
A method of separating out mixtures of liquids to show what is in them by letting them travel up a piece of chromatography paper
Chromatography method
1) draw pencil line on paper
2) place sample spot on line
3) place paper in solvent, with solvent below pencil line
4) allow solvent to soak up the paper
5) stop when solvent near top and mark how far it gets
Stationary phase
The substance the solvent moves through - usually paper
Mobile phase
The solvent
Rf
Retardation factor
Rf =spot distance/ solvent distance
Uses of rf
Rf enables you to identity a substance because for a given solvent and stationary phases, it is unique to each substance
Uses of chromatography
To tell between pure and impure substances
To identify substances by comparison with known ones
To identity substances by calculating Rf
Distillation
A method used to collect pure liquid from a solution, such as getting pure water from seawater
Condenser
A glass tube surrounded by a glass jacket containing cold tap water . Used to condense gases back to liquids
How distillation works
The solution is heated until it is hot enough for the solvent to boil. The solvent. Is then passed through a cool condenser where it turns back to liquid. The solute does not get hot enough to evaporate and stays where it is
Anti-bumping granules
Jagged grains of glass that are added during distillation to prevent violent boiling
Fractional distillation
A type of distillation used to separate mixtures of two or more liquids
How fractional distillation works
The liquid with the lowest boiling point boils first and can be collected, then the next boils and so on
Fractionating column
A tall glass column used during fractional distillation that gives a better separation of the liquids by producing a temperature gradient
Portable water
Water that is safe to drink
Desalination
Producing pure water from seawater
Purifying seawater
The seawater is distilled: heating the water to produce water vapour and condensing it back to liquid. Uses lots of enters
Uses of pure water
Pure water has to be used when chemists analyse substances to fins out what they contain. Tap water contains many dissolved substances that could interfere with this
Water treatment in the UK
Water is passed through a sedimentation tank, to allow sediment to settle out, it is passed through a filtration tower to remove floating particles, chlorine is added to kill bacteria
