EXPERIMENT 1 - RECITATION NOTES FOR EXPERIMENT # 5 A&B...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
EXPERIMENT 1: Chromatography- Separation of a Dye Mixture Name: Geerthana Jeyakumar Student Number: 211864980 Experiment Date: Monday, May 9, 2011 Submission Date: Monday, May 16, 2011 TA: Mitesh
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Introduction/Objective : Chromatography is a technique used to separate mixtures into its components. The purpose of this experiment is to use both TLC (Thin layer chromatography) and Column Chromatography to determine the purity and separation of both fluorescein dye and methylene blue, and to determine the best solvent for the separation of both dyes (95% ethanol versus K 2 SO 4 :H 2 O:CH 3 CN). Observations : When the TLC plate was placed within the K 2 SO 4 :H 2 O:CH 3 CN eluting solvent, the fluorescein dye and methylene blue moved up the TLC plate farther than when the TLC plate was placed in ethanol. In this solvent, the methylene blue moved along the plate up to 4.2 cm, while the fluorescein dye moved up to 4.6 cm. Purple impurities were visible slightly above the fluorescein dye and the methylene blue, when the TLC plate was placed in the eluting solvent K 2 SO 4 :H 2 O:CH 3 CN. When the TLC plate was placed within ethanol (95%) eluting solvent, the fluorescein dye spot moved up less that 0.1 cm, while the methylene blue moved along the plate up to 3.9 cm. Similar to the first solvent, there were purple impurities visible on the TLC plate, slightly above the mark where methylene blue and fluorescein dye stopped eluting. In column chromatography, the 95% ethanol brought the methylene blue down which was observed by the dark blue liquid that drained out of the column. It was noted that the fluorescein dye moved approximately 0.5cm down the column when the 95% ethanol was added. However, when sodium hydroxide was added to the column, the fluorescein dye, which was initially stationary, now migrated down the column and drained out as a bright greenish- yellow liquid.
Background image of page 2
Experimental Results : Table 1 : Thin Layer Chromatography (Eluting Solvent: K 2 SO 4 :H 2 O:CH 3 CN) Substance Distance Traveled (cm) R f Value Methylene Blue 4.2 0.82 Fluorescein Dye 4.6 0.90 Purple Impurity 4.9 0.96 Solvent Front 5.1 - Figure 1 : Sketch Of TLC Plate (Eluting Solvent: K 2 SO 4 :H 2 O:CH 3 CN)
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Table 2 : Thin Layer Chromatography (Eluting Solvent: 95% Ethanol) Substance Distance Traveled (cm) R f Value Methylene Blue 3.9 0.76 Fluorescein Dye 0.1 0.02 Purple Impurity 4.8 0.94 Solvent Front 5.1 - Figure 2 : Sketch Of TLC Plate (Eluting Solvent: 95% Ethanol)
Background image of page 4
Discussion/Conclusions Thin layer chromatography (TLC) and column chromatography are two distinct techniques used to separate a mixture into its components. In TLC, alumina, silica gel or any other solid adsorbent on a thin layer plate, is spotted 1cm from the bottom with a sample of a mixture, and placed in an appropriate eluting solvent with a depth less than 1 cm. As the eluting solvent rises up the plate by capillary action, it passes the mixture and generates equilibrium with the mixture. The strength of which the mixture bonds to the
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 06/06/2011 for the course CHEM 2020 taught by Professor Potvin during the Spring '09 term at York University.

Page1 / 13

EXPERIMENT 1 - RECITATION NOTES FOR EXPERIMENT # 5 A&B...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online