For 11th and 12th grade students, an investigatory project on the topic "Chalk Chromatography". Subject: Chemistry. That's all folks, see ya :)

2. CHEMISTRY
INVESTIGATORY
PROJECT
ON
CHALK
CHROMATOGRAPHY
NAME: ASHNA

3. CLASS:
XII
SECTION: ‘C’
ROLL NO.: 1
Lovely Public Sr. Sec. School
Chemistry Department
CERTIFICATE
This is to certify that Ashna, a student of class
XII-C has successfully completed the research
on the below mentioned project under the
guidance of Mrs. Rampal Mam (Subject Teacher)

4. during the year 2016-17 in partial fulfillment of
chemistry practical examination conducted by
AISSCE, New Delhi.
Signature of external examiner Signature of chemistry teacher
INDEX
 Certificate
 Aim
 Introduction
 Theory
 Apparatus and Material required
 Procedure followed

5.  Observations
 Uses of Chromatography
 Precaution
AIM OF THE PROJECT
To separate the color components
present in the sketch pen ink (given
below) by ascending chalk
chromatography and find their Rf value.
 Green

6.  Brown
 Black
INTRODUCTION
Chromatography is a laboratory technique for the
separation of a mixture. The mixture is dissolved in a
fluid called the mobile phase, which carries it through a
structure holding another material called the stationary
phase. The various constituents of the mixture travel at
different speeds, causing them to separate. The
separation is based on differential partitioning between
the mobile and stationary phases. Subtle differences in a
compound's partition coefficient result in differential

7. retention on the stationary phase and thus changing the
separation.
Chromatography may be preparative or analytical. The
purpose of preparative chromatography is to separate
the components of a mixture for more advanced use
(and is thus a form of purification). Analytical
chromatography is done normally with smaller amounts
of material and is for measuring the relative proportions
of analytes in a mixture.
Theory
In Chalk Chromatography, there is a stationary phase which is
the dusty Chalk and the mobile phase which is a liquid solvent
(or mixture of solvents) used to carry the sample solutes under
analysis along the chalk. Usually, one uses chromatography to
find out the components of a sample which are separated
depending how much soluble these are in particular solvents
and hence how far they travel along the chalk.
In order to make the technique more scientific rather than a
mere interpretation by sight, the Retention Value (Rf value for
short) was applied in chromatography. A particular compound

8. will travel the same distance along the stationary phase by a
specific solvent (or solvent mixture) given that other
experimental conditions are kept constant.
The Rf value is defined as the ratio of the distance moved by
the solute (i.e. the dye or pigment under test) and the distance
moved by the solvent (known as the Solvent front) along the
chalk, where both distances are measured from the common
Origin or Application Baseline, that is the point where the
sample is initially spotted on the paper.
Rf Value = Distance from Baseline travelled by Solute
Distance from Baseline travelled by Solvent
APPARATUS AND MATERIAL
REQUIRED
 Sketch pen ink(green, brown and
black)

9.  Beaker
 Water
 Three Chalks
 Ruler
 Pencil
PROCEDURE FOLLOWED
1. Take a chalk of approximately 7 cm.
2. Draw a horizontal line from pencil at distance of 1 cm from the base
of the chalk. Mark a point with pencil on the line drawn.
3. Spot the color ink directly with a sketch pen at the point marked
before. Care should be taken that the spot is small in size. Repeated
spotting may be done to enrich the spot, to increase the
concentration of component.

10. 4. Take a clean beaker and fill it with 1-2 ml of water. There should be
no droplets sticking inside the walls of beaker.
5. Insert the chalk carefully in the beaker so that only the spot on the
chalk remains above the solvent (water).
6. Keep the beaker in a safe place and leave it undisturbed.
7. Notice the rise of the solvent and the components in the upward
direction.
8. After sometime, the spot will separate into different colors and the
solvent moves ahead of the colors.
9. Remove the chalk from the beaker, Dry the chalk and mark the
levels of the solvent and color spots from the horizontal line drawn
before.
10. Record the observation in the tabular form.
11. Calculate the Rf value for various components.
OBSERVATIONS
Sket Color Distance Distance Rf

11. ch
pen
ink
used
compon
ent
obtaine
d
Travelled
by
component
(cm)
Travelle
d by
solvent(
cm)
val
ue
Gree
n
Blue 3 cm 4cm 0.7
5
yellow 3.4 cm 4 cm 0.8
5
Bro
wn
Blue 2.5 cm 4.5 cm 0.5
6
Red 3 cm 4.5 cm 0.6

12. 7
Yellow 3.8 cm 4.5 cm 0.8
4
Blac
k
Blue 2 cm 4 cm 0.5
Red 2.5 cm 4 cm 0.6
2

13. USES OF CHROMATOGRAPHY
 Pharmaceutical Company – determine amount of each
chemical found in new product.
 Hospital – detect blood or alcohol levels in a patient’s blood
stream.
 Law Enforcement – to compare a sample found at a crime
scene to samples from suspects.
 Environmental Agency – determine the level of pollutants in
the water supply.
 Manufacturing Plant – to purify a chemical needed to make a
product.
 Biotechnology industry – establishing the purity or
concentration of compounds in biotechnological research.
 Biological application – Chromatography has many
applications in biology. It is used to separate and identify
amino acids, carbohydrates, fatty acids, and other natural
substances. Environmental testing laboratories use
chromatography to identify trace quantities of contaminants
such as PCBs in waste oil and pesticides such as DDT in
groundwater. It is also used to test drinking water and test air
quality. Pharmaceutical companies use chromatography to
prepare quantities of extremely pure materials. The food
industry uses chromatography to detect contaminants such as
aflatoxin

14. PRECAUTIONS
1. Press gently while spotting the chalk otherwise the
chalk particle will be stuck on the sketch pen nib.
2. Spot must not big in size.
3. Spot must be enriched by spotting at the same point
twice or thrice.
4. The spot should never be dipped in the solvent.
5. There should be no water droplets sticking to the
inside of the beaker
6. The solvent should be adequate.
7. The solvent must not be allowed to rise till the other
end of the chalk.
8. Rf value is to be calculated by measuring maximum
height of the colored spot.