c12 - chemical analysis Flashcards
define a pure substance
one made up of just one element or compound
give the test for water
turns white anhydrous copper sulfate blue
- only shows water is present and not that it is pure
give melting and boiling points of water
melting: 0 degrees celsius
boiling: 100 degrees celcius
define fixed points of a substance
melting and boiling points
what are a mixture’s fixed points like?
changes state over a range of temperatures, so a range of melting and boiling points
how can you distinguish between pure and impure substances?
impurities lower the melting point of a substance and raise its boiling point
define a formulation
- a mixture designed to produce a useful product
- each chemical has a specific purpose
give an example of a formulation
paint contains pigment, binder (to help paint attatch to object), and a solvent (to help spread)
give 8 examples of formulations
1) fuels
2) alloys
3) fertilisers
4) cleaning agents
5) paints
6) medicines
7) cosmetics
8) food products
give equation relating to paper chromotography practical
retention factor = distance moved by substance/ distance moved by solvent
give two phases in chromotography
mobile phase - solvent
stationary phase - paper
give test for hydrogen gas
hold lighted splint at open end of test tube, squeaky pop sound if hydrogen is present
give test for oxygen gas
glowing splint in test tube relights if oxygen is present
give test for carbon dioxide gas
bubble gas through limewater and limewater turns milky if carbon dioxide is present
give test for chlorine
damp blue litmus paper is held in mouth of test tube and turns white if chlorine is present
- chlorine is a toxic gas
