Paper 2 - Chemical analysis Flashcards
What is a pure substance?
is not mixed with any other substances
when does a pure substance melt?
At a specific fixed temperature (specific fixed boiling point) the line is straight and not diagonal on a graph
what is a formulation?
A complex mixture that has been designed as a useful product e.g. fuels, cleaning products, paints, medicines
Chromatography?
take a piece of chromatography paper and draw a pencil line near the bottom. Then put the dots of our colours on the pencil line. Next place the bottom of the paper in a solvent (a liquid that dissolves substances). the solvent now moves up the paper and dissolves the inks, and the two coloured dots are also carried up the paper
in chromatography, how do you know if a colour was pure?
Because there’s only one spot on the paper
In chromatography, how do you know if a colour is a mixture?
if the colour has separated into two different colours
How do we test for hydrogen?
remove the top of the tube and insert a burning splint. Hydrogen gas burns rapidly and produces a pop sound
how do we test for oxygen?
insert a glowing splint into the tube. If it is oxygen, the splint will relight into flames.
how do we test for carbon dioxide?
Take some of the carbon dioxide solution and put it into a tube of limewater. If we repeat this several times, the limewater may turn cloudy (carbon dioxide)
How do we test for chlorine?
insert a damp litmus paper into the mouth of the test tube. Chlorine will bleach the litmus paper and turn it white