U1 T9 Chemical Analysis Flashcards
What is an element?
A substance that contains only one type of atom and cannot be broken down into anything simpler by chemical means
What is a compound?
A substance that consists of two or more elements chemically bonded
What is a mixture
Two or more substances mixed together, usually easy to separate
What can be used to measure purity of an element or compound?
Using data from the melting and boiling point and the chromatography
What is the melting point?
The temperature at which a given material changes from a solid to liquid or vice verse
What is the boiling point?
The temperature at which a given material changes from a liquid to a gas or vice versa
What five ways can mixtures be separated?
Filtration, Crystallisation, Simple distillation, Fractional distillation, And paper chromatography
What is chromatography used to separate?
2 or more substances in a solution e.g food dyes
How do you measure Rf values?
Distance moved by sample
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Distance moved by solvent
What is potable water?
Water that is safe to drink
Where do we find potable water?
Water from fresh water, eg silent valley, and sea water
What is desalination
The process of removing dissolved substance from sea water
What are the disadvantages of producing drinking water through distillation?
It’s expensive, increases need for non renewable energy, carbon dioxide emissions contribute to global warming
What colour change does anhydrous copper (II) sultans undergo in the presence of water?
White to blue
What colour does lithium burn?
Crimson