A useful mixture where the exact quantities of each element or compound inside have been specifically measured and thought out to make the product as useful as possible
Formulations
Paints
Fuels
Inks
Dyes
Melting point test
No clear melting point
Melting point is lowered
Boiling point is enlarged
Chromatography
Separates mixtures based on their solubility
The more soluble a material is, the further up the chromatography paper it travels
Calculating RF values
1. Distance moved by the solute / Distance moved by the solvent
2. RF values are always less than 1
3. RF values are unitless
Using RF values
Can identify which compounds or elements were present in the mixture
Many scientists have done these experiments before, so your RF value should be similar to what they got
Gas tests
1. Hydrogen - Squeaky pop sound
2. Chlorine - Damp litmus paper bleaches white
3. Carbon dioxide - Bubbles through limewater, forms cloudy precipitate
4. Oxygen - Glowing splint relit
Identifying positive and negative ions
1. Flame test - Identify metal ion
2. Sodium hydroxide - Identify positive ion based on precipitate colour and solubility
Flame test colours
Lithium - Crimson red
Sodium - Yellow
Potassium - Lilac
Calcium - Orange
Copper - Green
Identifying negative ions
1. Carbonate - Add hydrochloric acid, fizzing and carbon dioxide released
