C12.1-12.3 Flashcards
What is a pure substance?
A pure substance is one that is made up of just one substance
What is a formulation?
A mixture of compounds that is designed to produce a useful product
What can be used to distinguish between pure and inpure substance?
Pure elements and compounds melt and boil at specific temperatures
Inpure substances usually have a higher BP than pure substances
Whats an impure substance?
A mixture of 2 or more elemetns or compounds
Describe the steps in paper chromatography?
1) start line is drawn near the bottom of the paper
2) use a pipette to add spots of ink to the line
3) place the paped into a container with a suitable solvent in the bottom
4) the solvent travels up the paper, seperating the components
5) take the paper out before it reaches the top
6) paper is dried
7) measure the distance travelled by each spot and by the solvent to find out the rf value
How is Rf caculated?
Distance travelled by the substance / distance moved by solvent
What are safety precuations needed when doing chromotoghraphy?
Wear safety gloves
Ensure there is ventilation or use a fume cupboard to avoid breathing difficulties
What is the mobile phase?
solvent that moves through the paper, carrying different substances with it
What is the stationary phases?
What is contained on the paper and does not move through it
How do you distiguinsh between a pure and inpure substance on a chromotography?
A pure substance produces one spot
An inpure substance produces two or more spots
What are the tests for hydrogen?
Squeaky pop with burning splint in a test tube of hydrogen
What is the test for oxygen?
Insert a glowing splint in a test tube of oxygen if it relights oxygen is present
What is the test for co2?
Co2 turns limewater milky, a lighted wooden splint goes out in a test tube
What is the test for chlorine?
It makes damp blue litmus paper turn red and then bleaches it white
