info.improove@gmail.com
+91 81788 23424

Experiment 29: Paper chromatography

Experiment 29: Paper chromatography

Objective

To understand the principles of chromatography

Materials required:

  • Filter paper strip
  • solvent (absolute alcohol)
  • ink(s)
  • chalk

Procedure

  • Take a filter paper strip and using a pencil draw a horizontal line 3cm from one end of the paper. Then draw another line lengthwise (vertically) from the centre of the paper. Name the point at which the two lines intersect as P
  • Put a drop of the mixture of red and blue inks at the point P. Let it dry in air. Put another drop on the same spot and dry again, so that the spot is rich in the mixture
  • Pour 20mL of denatured alcohol and water in a beaker chamber and mix it well using a glass rod. This is used as the solvent.
  • Suspend the filter paper vertically in the chromatographic chamber containing the solvent in such a way that the pencil line remains about 2cm above the solvent level
  • Keep the set-up undisturbed for 15-20 minutes

Observations and Findings:

  • After the solvent has risen about 15 cm you will notice two different spots of blue and red colors on the filter paper. The pattern is called chromatograph.

Conclusions:

  • Over time, we see a pattern composed of various colors / components of the ink

Theory:

  • Most inks (and organic compounds in general) contain several impurities. Chromatography is a separation technique to extract pure compounds
  • Chromatography is a laboratory technique for the separation of a mixture.
  • The mixture is dissolved in a fluid (gas, solvent, water, ...) called the mobile phase, which carries it through a system (a column, a capillary tube, a plate, or a sheet) on which is fixed a material called the stationary phase.
  • The different constituents of the mixture have different affinities for the stationary phase.
  • The different molecules stay longer or shorter on the stationary phase, depending on their interactions with its surface sites.
  • So, they travel at different apparent velocities in the mobile fluid, causing them to separate.
  • The separation is based on the differential partitioning between the mobile and the stationary phases.
  • Subtle differences in a compound's partition coefficient result in differential retention on the stationary phase and thus affect the separation

Experiment-based learning kits

img
Chemistry Lab in A Box (Upto Class 10)

Comprehensive chemistry kit for Class 6 to 10

  • All reagents and lab equipment needed to do over 33 experiments as per Board syllabus

  • High quality and safe lab reagents

  • Videos of all the experiments Detailed instruction booklet with theory, concepts and procedures

MRPRs 4,499/-
AmazonRs 2,349/-
Buy on Amazon
FlipkartRs 2,399/-
Buy on Flipkart
HereRs 1,999/-
Buy Now
img
Refill for home experiment kits

Set of chemicals and reagents for home experiments

  • Support for all major science activity kits like Kutuhal, Einstein Box, Genius Minds, etc.

  • High quality and safe lab reagents

  • Strict quality testing procedures to ensure safety while doing experiments

MRPRs 2,499/-
AmazonRs 1,149/-
Buy on Amazon
FlipkartRs 1,199/-
Buy on Flipkart
HereRs 999/-
Buy Now!!
img
Basic chemistry equipment (starter kit)

Basic equipment to generate excitement towards science

  • Basic set of equipment like test tubes, holder, cleaner, filter papers, pipettes, litmus papers, etc.

  • High quality and safe lab equipment

  • Good starting point for children (suitable for children aged 7-10 years)

MRPRs 1,499/-
AmazonRs 499/-
Buy on Amazon
FlipkartRs 499/-
Buy on Flipkart
HereRs 449/-
Buy Now!!
img
Crystallography @ home

Make bright-colored crystals of different shapes and sizes

  • All reagents and equipment needed to make bright crystals - from multiple compounds

  • Instruction booklet and videos

  • Learn about crystallography - crystal shapes, solubility, effect of temperature, etc.

MRPRs 1,499/-
AmazonRs 1,149/-
Buy on Amazon
FlipkartRs 1,149/-
Buy on Flipkart
HereRs 999/-
Buy Now!!