EXERCISE 3

Question 1

the process of separating the susbtances in a complex mixture by their different affinities to an adsorbent

Answer 1

CHROMATOGRAPHY

Question 2

it is one of the most useful methods of separating the components of minute amount of mixture

Answer 2

CHROMATOGRAPHY

Question 3

commonly used for analyzing mixtures of colored chemicals

Answer 3

CHROMATOGRAPHY

Question 4

• a liquid or solid that is fixed in a place during the process
• usually a high quality filter paper, or an adsorbent

Answer 4

stationary phase

Question 5

• either liquid or gas which moves the samples through the stationary phase during the process
• solvent or a mixture of solvents

Answer 5

mobile phase

Question 6

stationary phase in column chromatography

Answer 6

adsorbent - alumina

Question 7

as additional mobile phase comes along, some or all the mixture will ____; this adosrption process continues along the length of the column

Answer 7

dissolve and continue moving

Question 8

if a proper choice of mobile phase, stationary phase, solvent and other operating parameters was made, the mixture will be separated in the column and its various components will ____

Answer 8

emerge at different times

Question 9

components of the sample will separate readily according to how strongly they ____ versus how readily they ____

Answer 9

adsorb on the stationary phase vs dissolve in the mobile phase

Question 10

organic compounds interact with ____ at different rates and interaction

Answer 10

adsorbents

Question 11

weak Van der Waals forces of attraction for the adsorbent

Answer 11

nonpolar

Question 12

dipole-dipole interactions or hydrogen bonding

Answer 12

polar

Question 13

____ absorb strongly on stationary phase

Answer 13

polar

Question 14

____ will be only weakly absorbed, and thus, has higher affinity with the mobile phase

Answer 14

nonpolar

Question 15

how does the sample moves in column chromatography

Answer 15

travels downward

Question 16

as the mobile phase and the** compound mixture** moves along the stationary phase, the compounds separate, largely dependent on the difference in their _____

Answer 16

degree of adhesion to the alumina

Question 17

column chromatography is useful in ____ in drugs

Answer 17

isolating active components

Question 18

mobile phase used

Answer 18

n hexane

Question 19

the mobile phase must ____ the height of the stationary phase

Answer 19

not exceed

Question 20

RESULT

second test tube

Answer 20

yellow

due to methyl red

Question 21

RESULT

3rd test tube

Answer 21

violet

switched to more polar solvent

Question 22

RESULT

1st test tube

Answer 22

clear - n hexane

Question 23

RESULT

4th test tube

Answer 23

clear - ethanol

Question 24

which is more polar?
crystal violet or methyl red

Answer 24

crystal violet

Question 25

**crystal violet** will be **adsorbed** to the **alumina** more ____

Answer 25

strongly

Question 26

____ will **elute off** the colum with a **nonpolar** solvent n-hexane

Answer 26

methyl red