Chemical Analysis Flashcards
What are pure substances
Substances that contain only 1 type of element or compound
Compare pure and non pure substance melting point
Pure melts sharply at a single point
Non-pure melts over a range of temperatures
What are formulations
Mixtures of compounds or substance that do not react with each other
Example of formulations
Deodrants, sun cream, medicines
When is chromatography used
Separate mixture of soluble substances
Mobile phase
Solvent
Stationary phase
Paper
Pure substances in chromatography have
1 spot
Rf value equation
Distance travelled by substance/ distance travelled by solvent
Chromatography practical
1 cm pencil line from bottom of absorbtion paper
Use pipette to drop small spots of the substances onto the pencil line
Pour solvent into beaker and hang stationary phase so the solvent just touches the bottom of the paper
Solvent moves up paper
Remove paper just before solvent reached top
Measure distance traveled by solvent
Measure distance travelled by each ink spot
Workout Rf values and compare
Test for hydrogen
Squeaky pop test
Lit splint pops
Test for oxygen
Splint relights
Test for Carbon dioxide
When ran through limewater turns cloudy
Test for chlorine
Litmus paper turns white
What is used to put metals into a flame in the flame test
Nichrome wire
All flame tests
Lithium Crimson
Sodium Yellow
Potassium Lilac
Calcium Orange-red
Copper Green
Sodium hydroxide tests
Aluminium White ppt
Calcium White ppt
Magnesium White ppt
Copper Pale Green ppt
Iron 2+ Dirty Green ppt
Iron 3+ Rusty Brown ppt
Spectator ions
Ions that are not involved in a reaction
Test for carbonate ions
Add HCl
Bubble that Carbon dioxide through limewater and it turns cloudy
Test for sulfate ions
Add HCl and barium chloride
White ppt formed
EXCEPT BARIUM SULFATE
Test for halide ions
Add nitric acid and silver nitrate
Chloride White ppt
Bromine Cream ppt
Iodine Yellow ppt
Benefits of flame emission spectroscopy
Fast accurate sensitive
Why is flame emission spectroscopy used
Identify metal ions in a solution
How does flame emission spectroscopy work
1 Sample heated in flame
2 Electrons in metal ions move to higher levels
3 Electrons fall back into lower levels and release light
4 Wavelength is measured by instruments
5 Compared with metal ion wavelengths