C1 - Mixtures And Chromatography

Question 1

What are mixtures?

Answer 1

Lots of seperate things mixed/combined together

Question 2

What is different in a mixture compared to a compound?

Answer 2

There is no chemical bond between them

Question 3

What can parts of the mixture either be?

Answer 3

Elements or compounds

Question 4

How can mixtures be serparated out?

Answer 4

Physical methods such as:

• Filtration
• Crystallisation
• Simple distillation
• Fractional distillation
• Chromatography

Question 5

Is air a mixture?

Answer 5

Yes

(It is made up of MAINLY nitrogen,oxygen,carbon dioxide and argon)
(The gases in air can be separated fairly easily)

Question 6

Is crude oil a mixture?

Answer 6

Yes

(It is a mixture of different length hydrocarbon molecules)

Question 7

Are elements chemical properties affected by it being a mixture?

Answer 7

No,the properties of a mixture are just a mixture of the properties of the SEPERATE parts meaning that the chemical properties arent affected by it being a mixture

Question 8

What is chromatography used for?

Answer 8

Separating substances in a mixture,the technique can be used to separate different dyes in an ink

Question 9

How does paper chromatography work?

Answer 9

1) Draw a line near the bottom of a sheet of filter paper
(Use a pencil to do this - pencil marks are insoluble and wont dissolve in the solvent)

2) Add a spot of the ink to the line and place the sheet in a beaker of solvent,e.g water

3) The solvent used depends on whats being tested.Some compounds dissolve well in water,but sometimes other solvents like ethanol are needed

4) Make sure thd ink isnt touching the solvent - You dont want it to dissolve into it

5) Place a lid on top of the container to stop the solvent evaporating

6) The solvent seeps up the paper,carrying the ink with it

7) Each different dye in the ink will move up the paper at a different rate so the dyes will seperate out.Each dye will form a spoy in a different place - 1 spot per dye in the ink

8) If any dof the dyes in the ink are insoluble (wont dissolve) in the solvent youve used,theyll stay on the baseline

9) When the solvent has nearly reached the top of the paper,take the paper out of beaker and leave it to dry

10) The end result is a pattern of spots called a chromatogram