Chemistry S3 Flashcards
Name the seven separation techniques.
Magnetism, Evaporation, Chromatography, Filtration, Electrolysis, Heating and Distillation.
Explain Soluble.
When a Solute (solid) dissolves in a solvent (liquid) it is said to be Soluble.
What is a Solute?
A Solute is a solid that is added to a liquid.
What is a Solvent?
A Solvent is the liquid the solute is added to.
What is a Solution?
A Solution is the dissolved mixture of the Solute and Solvent.
What is a Saturated Solution?
A saturated solution is one in which any additional solute added to the solution is no longer dissolved.
What is Diffusion?
Diffusion is when the particles travel from an area of high concentration to an area of low concentration.
Explain Chromatography.
Chromatography can be used to separate mixtures of coloured compounds. Mixtures that are suitable for separation by chromatography include inks, dyes and colouring agents in food.
Simple Chromatography experiment.
Simple chromatography is carried out on paper. A spot of the mixture is placed near the bottom of a piece of chromatography paper and the paper is then placed upright in a suitable solvent, eg water. As the solvent soaks up the paper, it carries the mixtures with it. Different components of the mixture will move at different rates. This separates the mixture out.
Explain Rf values.
Different chromatograms and the separated components of the mixtures can be identified by calculating the Rf value using the equation:
Rf = distance moved by the compound ÷ distance moved by the solvent.
The Rf value of a particular compound is always the same - if the chromatography has been carried out in the same way. This allows industry to use chromatography to identify compounds in mixtures.
Reactivity of Metals.
If an acid is added to a metal, the metal will be quickly corroded by the acid. You can see the reaction happening because the mixture fizzes and the metal eventually disappears. some metals are more reactive than others - Gold for example is so un-reactive that nothing happens.
Metal + Acid = Salt + Hydrogen
What is the rhyme to help place the metals in order of reactivity?
Postman Sends Cards (with) Money And Coins (to the) Zoo In Liverpool. His Coins (were) Silver, Gold, Platinum.
Place the metals in order of reactivity from most reactive to least reactive?
Potassium, Sodium, Calcium, Magnesium, Aluminium, Carbon, Zinc, Iron, Lead, Hydrogen, Copper, Silver, Gold, Platinum.
