pre lab quiz 5

Question 1

It means color writing

Answer 1

Chromatography

Question 2

Chromatography literally means

Answer 2

Color writing

Question 3

Chromatography is a method of separating the…

Answer 3

Components of the mixture

Question 4

Chromatography is widely used for _____ and _____ analyses or for _____ and _____ of the components of a mixture

Answer 4

Quantitative
Qualitative
Isolation
Recovery

Question 5

These components have different affinities and distributes between 2 phase:

Answer 5

Stationary phase
Mobile phase

Question 6

The mobile which can be a ____ or a _____, that moves in ___________ and passes over the ______

Answer 6

Liquid
Gas
Definite direction
Stationary phase

Question 7

The components of the mixture are introduced at _____

Answer 7

One end of the stationary phase

Question 8

As the stationary and mobile phase interacts with one another, different compounds migrate at ____ and ______ based on their ____.

Answer 8

Different rates
Separate from one another
Affinities

Question 9

A substance that has stronger attractive forces with the ______ will migrate more _______ than a substance that has weaker attractive force

Answer 9

Stationary phase
Slowly

Question 10

The ability of a substance to ______ in and move with the _____ phases enables it to travel more easily over the _____ phase

Answer 10

Dissolve
Mobile
Stationary

Question 11

What are the 4 types of chromatography

Answer 11

TLC
LC
HPLC
GC

Question 12

The most suitable chromatography is based on
1)
2)
3)
to separate

Answer 12

1) purpose of the separation
2) available resources
3) properties of the compounds

Question 13

In this experiment, thin layer chromatography will be used to analyze the _____ from the previous experiment

Answer 13

Extracted caffeine

Question 14

TLC is ____, ____ , ____, _____ and it requires only _____ quantities of material

Answer 14

Simple, inexpensive, fast and efficient
Small

Question 15

In TLC, various materials can be used as the _____ phase

Answer 15

Stationary phase

Question 16

_____, _____, or _____ are coated with a thin layer of adsorbent, can be used as a stationary phase

Answer 16

Glass
Metals
Plastic plates

Question 17

Glass, metals or plastic plates are coated with a_____, can be used as a stationary phase

Answer 17

Thin layer of absorbent

Question 18

The mobile phase is _____ solvent or a _____ of solvents

Answer 18

Pure
Mixture

Question 19

The appropriate composition of the mobile phase depends on the _____ in the mixture being separated

Answer 19

Polarities of the compound

Question 20

The stationary phase is usually ____ - _____ is _____ widely used

Answer 20

Polar - silica gel
Most

Question 21

The stationary phase is polar -

Answer 21

Silica gel is most widely used

Question 22

What is the formula of the Rf

Answer 22

Distance traveled by the solute (mm) / distance traveled by the solvent form (mm)

Question 23

What are 3 objectives of this activity

Answer 23

Perform thin layer chromatography
Check the purity of the extracted crude caffeine from previous experiment
Calcite the Rf value of the crude caffeine

Question 24

What are the reagents used (MIC)

Answer 24

Methanol
Iodine crystals
Chloroform

Question 25

What are the needed glassware

Answer 25

2 beaker 250ml 2 beaker 100ml 2 test tube 2 watch glass 1 stirring rod 1 graduated cylinder 1 capillary tubes

Question 26

What is the instrument used

Answer 26

UV lamp

Question 27

To perform TLC analysis, a small amount of the mixture is being separated is dissolved in a _____ and applied or spotted onto the ____________

Answer 27

Suitable solvent Adsorbent near one end of a TLC plate

Question 28

Then, the plate is places in a closed chamber with the edge nearest the ______ immersed in a _____ layer of the _____ phase called the, ______

Answer 28

applied spot shallow mobile phase developing solvent

Question 29

Where is the plate placed at

Answer 29

Closed developing chamber

Question 30

The solvent rises through the stationary phase by _______ , a process called developing the chromatogram

Answer 30

capillary action

Question 31

The solvent rises the rough the stationary phase by capillary action, a process called ______

Answer 31

Developing the chromatogram

Question 32

After allowing the chromatogram to develop, the _____ can be marked and the distance travelled by the ________ and ______ can be measured

Answer 32

Spots Solvent front Spots

Question 33

Rf

Answer 33

Retardation factor

Question 34

It is a dimensionless quantity that can be used as a measure of the affinity of the spot towards the stationary or mobile phase

Answer 34

Rf - retardation factor

Question 35

High value of Rf =

Answer 35

High affinity towards the mobile phase

Question 36

Do not look directly in the...

Answer 36

Uv lamp

Question 37

What can be disposed directly to the sink with running water

Answer 37

Diluted aq solutions Acid wastes that can be diluted with water

Question 38

Chloroform molecular formula

Answer 38

CHCl3