chromotohaprahy

Question 1

is thin layer chromtoprahy?

Answer 1

mobile phase: metal, glass plate, silica aliminia,
= line drawn in pencil
= placed in solvent,above the solvent
= leave until solvent has moved near to the top, mark the solvent front quikly, prvents eavporation

Question 2

How do we see colourless compounds?

Answer 2

= iodine or floruscent dyes
= UV light
=

Question 3

How do we use floruscent dyes and uv radiation?

Answer 3

= add flourscent dye, to lamp seen by uv light
= colourless spots on chromatgram, will block any glow
= draw round thes espots

Question 4

Hw do we use iodine?

Answer 4

= place in sealed jar with few iodine crystaks
= iodine vapour stixks to chemials on plate tunin purple
= vapour is locating agent

Question 5

How does column chtomrkoraphy work?

Answer 5

= seperating and purfying, larger quantities in a mixture
= bureete, collumn, packed with silica or alumina, staionay phase
= mixture and solvent is run through collmu, continousy
= different compounds, run throufh collum n at different rates, come out bottom at different times

Question 6

how does gas chromotoraphy work?

Answer 6

= seperate a mixture of liquid that are volatile and can be identified
= uses a collumn but this is thin and wounded inside of a oven to save space
= lined with solid or viscous liquid, oil, stationay phas
e=
= sample is injected itno machine and carried by an inert gas- mobile phase
=
= sustances take a different amount of time to travel theough collumn and to the detector- retention time
=

Question 7

How do we calculate r values?

Answer 7

= distance trabelled by the spot/ distabce travelled by the solvent

Question 8

In gas chromotorhaphy what does the timeit takes for it to move through the sample depend on?

Answer 8

= some molecules may stay more stuck on the stationary phase
= some may spendmore travelling through the mboile phase