SBA #13 - Paper Chromatography

SBA # YY MM DD
13 2022 05 19
Title: Paper Chromatography
Aim: To investigate the pigments in dye
Material/Apparatus:
● chromatography paper strip
● colored dye solution
● pencil
● distilled water
● glass rod
● ruler
● 250 ml beaker
● test tube rack
● boiling tubes
● measuring cylinder
● tape
● scissors
Procedure:
1. A pencil was used to draw a faint horizontal line 4 cm from the tip of the
filter paper.
2. Another line was drawn to cross the horizontal line previously drawn at its
center.
3. Where the two lines intersected, a small pinhead was used to apply a tiny
dot of dye.
4. The chromatography paper was secured to the glass rod using tape.
5. The filter strip was placed into a test tube containing 2cm3 of distilled
water, which acts as a solvent. The filter paper was not allowed to stick to
the wall of the test tube.
6. The test tube was placed in the rack and was left undisturbed, but it was
noted when the solvent was almost at the top.
7. The paper was removed from the test tube and with a pencil, the level to
which the solvent rose was marked. This was called the solvent front.
8. The distance of the solvent from the original line was measured.
FOR TEACHERS ONLY

SKILLS ASSESSED M/M ORR A/I P/D D CL/F
MARK OBTAINED
SBA # YY MM DD
13 2022 05 19
9. The filter paper was dried and pencil marks were made at the center of each
color which advanced from the original spot.
10. The distance of each color from the original line was measured.
𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑡𝑟𝑎𝑣𝑒𝑙𝑙𝑒𝑑 𝑏𝑦 𝑡ℎ𝑒 𝑐𝑜𝑚𝑝𝑜𝑛𝑒𝑛𝑡 𝑓𝑟𝑜𝑚 𝑡ℎ𝑒 𝑜𝑟𝑖𝑔𝑖𝑛𝑎𝑙 𝑙𝑖𝑛𝑒 (𝑐𝑚)
11. The formula Rf = 𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑡𝑟𝑎𝑣𝑒𝑙𝑙𝑒𝑑 𝑏𝑦 𝑡ℎ𝑒 𝑠𝑜𝑙𝑣𝑒𝑛𝑡 𝑓𝑟𝑜𝑚 𝑡ℎ𝑒 𝑜𝑟𝑖𝑔𝑖𝑛𝑎𝑙 𝑙𝑖𝑛𝑒 (𝑐𝑚) was
used to calculate the Rf values of each of the colors obtained.
Diagram
FOR TEACHERS ONLY

MARK OBTAINED
SBA # YY MM DD
13 2022 05 19
Observations/Results:
Table showing information of each component obtained

Color of component Distance traveled by Distance traveled by Rf Value
observed the component from the solvent from the
the original line (cm) original line
green 6 cm 6 cm 1
yellow 4 ½ cm 6 cm 0.75
pink 4 cm 6 cm 0.67
Analysis:
Paper chromatography involves placing a spot of the substance under investigation
near the end of a strip of absorbent paper similar to filter paper. In the experiment,
a chromatography paper strip was placed in a boiling tube containing distilled
water. A dot of ink was placed on the chromatography paper strip. Over the period
of 10 minutes, the different pigments of the ink were separated. The pigments
obtained were green, yellow, and pink. The different pigments obtained were
separated due to each pigment having a different solubility with water. When the
distilled water moves up the filter paper strip. the pigments of the ink move up at
different rates; the more soluble the pigment is, the faster it moves. The resulting
separation of pigments on the paper is called a chromatogram. Using this
information, it was observed that the green pigment had the highest solubility in
water, as it rose the highest, whilst the pink pigment had the least solubility in
water as it did not rise very high from the starting point. When the green pigment
rose to the maximum point, the solvent front was also observed. The solvent front
is the wet, moving edge of the solvent that progresses along the surface where the
separation of the mixture is occurring. After the distance of the solvent and the
distance of the different components from the original line were observed, these
observations were used to calculate the Rf value (retardation factor). The Rf value
is the ratio of the distance moved by the solute to the distance moved by the
solvent. The Rf value indicates how soluble a substance is.
FOR TEACHERS ONLY

MARK OBTAINED
SBA # YY MM DD
13 2022 05 19
Rf Values calculated for the pigments obtained:

● Rf Value for the green pigment: 6 ÷ 6 = 1 cm
● Rf Value for the yellow pigment: 4 ½ ÷ 6 = 0.75 cm
● Rf Value for the pink pigment: 4 ÷ 6 = 0.67 cm
Conclusion:
In conclusion, through this experiment, the pigments present in the ink were
separted by paper chromatography due to different solubilities in water. The
pigments obtained were green, yellow, and pink, with the green pigment having
the highest solubility in water and the pink pigment having the lowest solubility in
water.
Reflection;
In this experiment, I learnt how paper chromatography is used to separate
substances and why the different pigments are separated at different rates due to
their solubilities in the given substance. Paper chromatography can be applied to
the real world when analyzing food colors in different foods to ensure no
non-permitted coloring agents are added, causing illnesses.
FOR TEACHERS ONLY

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SBA #13 - Paper Chromatography

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SBA # YY MM DD

Title: Paper Chromatography

Aim: To investigate the pigments in dye

FOR TEACHERS ONLY

FOR TEACHERS ONLY

Table showing information of each component obtained

FOR TEACHERS ONLY

Rf Values calculated for the pigments obtained:

FOR TEACHERS ONLY

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