What is the mobile phase? | Where molecules can move |
What is the stationary method? | Where molecules cannot move |
What is an Rf value? | The ratio between the distance travelled by the dissolved substance [solute] and the distanced travelled by the solvent |
Rf = | distance travelled by substance [e.g ink spot] / distance travelled by solute [water or ethanol] |
What is the test for chlorine? | Bleaches damp litmus paper |
What is the test for oxygen? | Relights a glowing splint |
What are the tests for carbon dioxide? | Puts out a lit splint
Turns limewater cloudy when bubbled through |
What is the test for hydrogen? | Creates a squeaky pop when lit splint held at the end of test tube containing hydrogen |
Test for carbonate ions? | Add HCl acid to mystery solution connected to limewater
If carbonate ions are present, carbon dioxide is formed turning the limewater cloudy |
Test for sulphate ions? | Add HCl and Barium chloride solution to mystery solution
If white precipitate is formed, sulphate ions are present |
Test for halides? | Add dilute nitric acid and silver nitrate solution to mystery solution
If chloride is present, white precipitate is formed
If bromide is present, cream precipitate is formed
If iodide is present, yellow precipitate is formed |
Flame tests method | Sterilise platinum loop wire in HCl and blue flame
Dip loop in sample and put in flame
Record flame colour and sterilise
Repeat with different samples |
Lithium flame colour | Crimson |
Sodium flame colour | Yellow |
Potassium flame colour | Purple/ Lilac |
Calcium flame colour | Orange-red |
Copper flame colour | Green |
Metal hydroxide test | Add sodium hydroxide to mystery compound forming insoluble hydroxide
If coloured precipitate is formed this allows the metal to be identified |
Calcium precipitate colour | White |
Copper (II) precipitate colour | Blue |
Iron (II) precipitate colour | Green |
Iron (III) precipitate colour | Brown |
Aluminium precipitate colour | White then colourless |
Magnesium precipitate colour | White |