chemical analysis - chromatography

Question 1

what does paper chromatography allow

Answer 1

to separate substances based on there solubility

Question 2

what is the paper used in chromatography

Answer 2

chromatography paper

Question 3

why do we draw a pencil line at the bottom of the paper

Answer 3

so that we know where to out out substance being tested - should be done in pencil so that the ink oddest travel up the page

Question 4

what does the paper go into

Answer 4

a solvent

Question 5

what is the paper known as and why

Answer 5

the stationary phase because it does not move

Question 6

what is the solvent known as and why

Answer 6

the mobile phase as it moves up the paper

Question 7

using ink as an example, how do we know if a substance is pure

Answer 7

there will only be one color still, it would be impure if mulitiple colors appear

Question 8

which travels further a more or less soluble substance

Answer 8

a more soluble substance will travel further along the paper

Question 9

what is one of the benefits to chromatography

Answer 9

we can use it to identify and unknown substance

Question 10

how do we gather the data needed to work out the rf value

Answer 10

measure how far the substance moves - measure using a ruler from the pencil line to the dot
repeat with how far the solvent moved
- measure using a ruler from the pencil line

Question 11

how to work out rf value

Answer 11

distance moved by substance / distance moved my solvent

Question 12

what is the unit for rf values

Answer 12

they do not have a unit