topic 8 chemical analysis Flashcards
what does purity mean in chemistry
something that only contains one COMPOUND or ELEMENT throughout- not mixed with anything else
what are formations
mixtures with exact amounts of components
what are the 2 faces that paper chromatography has
1) a mobile phase
2) a stationary phase
what is a mobile phase
where particles can move, this is always a liquid or a gas
what is a stationary phase
where the molecules can’t move, this is always a solid or a really thick liquid
how to test for chlorine
- using litmus paper
- chlorine bleaches damp litmus paper, turning it white
- it ma turn red for a while that is because a solution of chlorine is acidic
how to test for oxygen
- using a glowing splint
- if you put a glowing splint inside a test tube containing oxygen, the oxygen will relight the glowing splint
how to test for carbon dioxide
- calcium hydroxide
- bubbling carbon dioxide through (or shaking carbon dioxide with) an aqueous solution of calcium hydroxide (known as lime water) causes the solution to turn cloudy
how to test for hydrogen
-if you hold a lit splint at the open end of a test tube containing hydrogen, you’ll get a “squeaky pop”
2 examples of what pure samples can be
- a single compound
- a single element
what is the easiest was to see how pure a substance is
by measuring its melting or boiling point
2 facts about pure substances
- they melt at a specific temperature
- they have a fixed boiling point
in formulations what happens to each quantity
it is carefully measured so that the product has the properties we need
what is a formulation
a complex mixture that has been designed as a useful product
3 examples of formulations
alloys, fuels and medicine
