Chemical Analysis
Key Words:
Pure - nothing has been added it's in its natural state. Contains one compound or element.
Formulations - mixtures with a precise purpose.
Chromatography - an analytical method to separate substances in a mixture.
Mobile phase - molecules can move, they are liquid or a gas.
Stationary phase - molecules can't move, they are solid or thick liquid.
Rf value - the ratio between the distance travelled by the dissolved substance and the distance travelled by the solvent.
Tests:
- Chlorine - turns litmus paper white.
- Oxygen - glowing splint will relight.
- Carbon Dioxide - added to limewater turns solution cloudy.
- Hydrogen - lighted splint will 'pop'.
- Carbonate ions - add drops of dilute acid, then connect to a tube of limewater. Turns solution cloudy.
- Sulfate ions - add drops of dilute hydrochloric acid & barium chloride solution. A white precipitate of barium sulfate will form.
- Halides ions - add drops of dilute nitric acid & silver nitrate solution:
- Chloride gives a white precipitate of silver chloride.
- Bromide gives a cream precipitate of silver bromide.
- Iodide gives a yellow precipitate of silver iodide.
- Lithium ions - burn a crimson in a flame.
- Sodium ions - burn yellow in a flame.
- Potassium ions - burn lilac in a flame.
- Calcium ions - burn orange-red in a flame.
- Copper ions - burn green in a flame
Flame Emission Spectroscopy - uses the intensity of light from a flame to produce a line spectrum.
PRACTICAL
Calculating R values
Watch the video and have a go at writing out the steps of the practical.
PRACTICAL
Identifying Ions
Watch the video and have a go at writing out the steps of the practical.
Links for Learning
Websites  Videos  Games  Quizzes
Find out what kind of learner you are and the best revision techniques for you.
Visit our Revision Tips page for more.
