chromatography

Question 1

what can be said about Rf if the sample does not dissolve

Answer 1

it is 0

Question 2

how is Rf used

Answer 2

by comparing the experimental results to known values

Question 3

what can Rf be affected by

Answer 3

temp of solvent
- the type of solvent used
- medium of experiment

Question 4

what is TLC

Answer 4

thin layer chromatography

Question 5

what is the most desired result in chromatography

Answer 5

max separation

Question 6

what do polar molecules dissolve in

Answer 6

polar solvents

Question 7

what type of bonds does ethyl ethanoate have

Answer 7

permanent dipole

Question 8

does water or ethanol have stronger hydrogen bonds

Answer 8

water

Question 9

the weaker the intermolecular forces….

Answer 9

the less polar it is

Question 10

what are some examples of non-polar solvents

Answer 10

heptane
octane
petrol

Question 11

what do non-polar molecules dissolve in

Answer 11

non polar solvents

Question 12

what is the purpose of the lid in TLC

Answer 12

to contain any evaporated solvent

Question 13

what is the purpose of the solvent soaked filter paper in TLC

Answer 13

• placed on the inside of the beaker

ensures the solvent doesn’t evaporate easily

Question 14

what are the methods of identifying dots

Answer 14

• UV
  -Ninhydrin to produce purple/pink dots
• iodine crystals ( let it evaporate and a series of brown dots will appear- must wear gloves so not to contaminate the sample