Chapter 8 Flashcards
What is a pure substance?
can be a single element or single compound not mixed with any other substance
How can we find out if a substance is pure?
melting and boiling points =
SPECIFIC AND FIXED
Impure substances melt and boil over a range of different substances
= heat a substance see if it’s pure
what is a formulation?
complex mixture designed as a useful product
In a formulation why are the quantities of each component measured?
measured carefully so that product has properties we need
examples of formulations?
Fuel Cleaning products Paints Medicines Alloys Fertilisers Good
How are formulations important in the pharmaceutical industry?
Altering formulations of a pill for example,
Chemists Male sure it delivers the drug to correct part of body at right concerntration and it’s consumable and long enough shelf life
what is paper chromatography?
Allows to seperate substances based on their different solubilities
Steps to paper chromatography
1 take piece of chromo paper and draw a pencil line near bottom
2 put a dot of first colour on pencil line and next to it put 2nd colour
3 place bottom of paper in solvent
4 solvent makes its way up paper and it dissolves ink the two coloured dots and carry up paper
whats mobile phase in chromo?
Solvent - because moves
Whats stationary phase in chromo?
Paper as doesn’t move
What does one dot tell us in chromo?
single pure substance and not mixture
what does two dots represent in chromo?
Mixture as has two dissolved substances
why does paper chromo work?
each chemical in the mixture will be attracted to the stationery phase to different extent
strongly attracted not move far
Weakly attracted move up the paper
why do we draw start line in pencil in chromo?
If we drew in pen the pen ink move up paper with the solvent
how do we test for hydrogen?
insert burning splint into test tube with hydrogen
Produces pop sound
As hydrogen burn quickly with oxygen in the air to = h20
