Revision for peridoc table and separation techniques Flashcards
What is a period?
Elements in the same horizontal row are said to be in the same period. The periods are numbered from top to bottom.
The period number is the same as the number of electron shells that are occupied.
What is a group?
A group is a downwards/vertical collum which has different elements which have different reaction and boiling points.
What are the displacement reactions in group 7?
The group 7 elements are also known as the halogens. They include fluorine, chlorine, bromine and iodine, which all have seven electrons in their outer shell.
In a displacement reaction, a less reactive element is displaced by a more reactive element.
What is solute
Solute: A solid substance that is dissolved into a liquid.
What is a pure substance?
A pure substance is a substance that has nothing added to it like calcium or sugar.
How could you test something is pure?
If something/compound is impure that means it has a melting point and a boiling point.
What is a mixture?
A mixture is made from molecules of elements and compounds that are simply mixed together, without chemical bonds. Mixtures can be separated using techniques such as filtration, chromatography, evaporation and distillation.
What is a solution?
A solution is the mixture that is produce when a solute gets dissolved into a solvent.
What is a solvent?
A liquid into which other substances can be dissolved.
What is solubility?
Something that can dissolve when mixed with a solvent
What is saturated?
A saturated solution is a chemical solution containing the maximum concentration of a solute dissolved in the solvent. Additional solute will not dissolve in a saturated solution.
How is filtration useful
Filtration is useful because it can filter dirty water into clean just by using things like evaporation and distillation and even filter paper/coffee filter paper.
Describe how to carry out chromatography
Chromatography can be carried out by using a piece of paper a pencil mark and a spot of pen ink. First you need to put the ink on the pencil mark and hold or connect to lolly pop stick and put in water. The water should be around 2,5cm high. The ink will be carried upwards by the absorbance of the paper in water.
Where is chromatography useful
Chromatography can be useful in some situations like when someone has stole something and put there signature on it in pen you can claim its them if they had that pen.
How does filtering work
Filtration is a method for separating an insoluble solid from a liquid when a mixture of sand and water is filtered.
