chromatography 2

Question 1

define chromatography

Answer 1

analytical technique that separates components in a mixture between a mobile phase and a stationary phase

Question 2

what is the stationary phase

Answer 2

solid/liquid on solid

Question 3

what is the mobile phase

Answer 3

liquid or gas

Question 4

what are the advantages of TLC

Answer 4

quick inexpensive

Question 5

what does TLC stand for

Answer 5

thin layer chromatography

Question 6

what does tlc do

Answer 6

indicates how many components are in a mixture

Question 7

what does adsorbent mean

Answer 7

solid silica holds the different substances in the mixture to its surface

Question 7

what is the TLC plate

Answer 7

plastic sheet/glass coated with thin layer of solid adsorbent (usually silica)

Question 8

what does the stationary phase do and how does it interact with the mobile phase

Answer 8

different components in mixture have different affinities for the absorbent and bond with different strengths to ints surface

Question 9

how to carry out tlc

Answer 9

1 onTLC plate, draw a pencil line across the plate = base line
2 Using a capillary tube, spot a small amount of a solution of the sample onto the base line on the plate.
3 Prepare a chromatography tank for the TLC plate.
(a small beaker with a watch glass placed on the top.) Pour some solvent into the beaker to a depth of about 0.5 cm.
4 Place the prepared TLC plate in the beaker, making sure that the solvent does not cover the spot. Cover the beaker with the watch glass and leave it The solvent will rise up the TLC plate

Question 10

how to calculate rf

Answer 10

distance moved by component/distance moved by solvent front

Question 11

what is gas chromatography used for

Answer 11

for separating and identifying volatile organic compounds

Question 12

what is the stationary phase In gas chromatography

Answer 12

high boiling point liquid adsorbed into an inert solid support

Question 13

what is the mobile phase in gas chromatography

Answer 13

inert carrier gas

Question 14

how to perform a gas chromatograph

Answer 14

Question 15

what is retention time

Answer 15

time taken for each component to travel through the column