Chemical analysis Flashcards
What is a pure substance?
A single element of compound not mixed with any other substance
What data can you use to distinguish pure substances from mixtures?
Melting point and boiling point
What is a formulation?
A mixture that has been designed as a useful product
How are formulations made?
By mixing the components in carefully measured quantities to ensure that the product has the required properties
What are some examples of formulations?
Fuels, cleaning agents, paints, medicines, alloys, fertilisers and foods
What is chromatography and how can it be used?
Can be used to separate mixtures and can get information to help identify substances
What does chromatography involve?
A stationary phase and a mobile phase
What does the separation depend on in chromatography?
The distribution of substances between the phases
How do you work out the RF value?
Distance moved by substance
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Distance moved by Solvent 
How can you identify a pure compound from chromatography?
It will produce a single spot in all solvents
What is the RF value?
The ratio of distance moved by a compound to the distance moves by the solvent
What is the test for hydrogen?
A burning splint held at the open end of a test tube of the gas and if there is hydrogen you will hear a squeaky pop sound
What is the test for oxygen?
Glowing splint inserted into a test tube of the gas if there is oxygen present the splint will relight
What is the test for carbon dioxide?
Lime water and you will know carbon dioxide is present when the lime water is shaken with the gas and it turns milky or cloudy
What is the test for chlorine?
Litmus paper and chlorine is present when the damp litmus paper is bleached and turns white
