Essay on Adsorption Chromatography

Submitted By ichester
Words: 1686
Pages: 7
Open Document
Ivy Chester, A96024600 A03 CHEM 143A 5/20/13

Lab Report 5: Separation of an unknown two-component mixture by distillation and identification of the components by GC analysis

Introduction:

The purpose of this experiment was to perform a simple distillation as well as a fractional

distillation in order to separate the contents of an unknown mixture (C) by boiling points. This was followed with an analysis by gas chromatography.

In a simple distillation there is the unknown which vaporizes and condenses at which

point it is collected. This is the most basic type of distillation. In this distillation the vapor rises from the boiling solution and condenses once it reaches the condenser where it is immediately collected as a fraction (1). During this process the solution is kept at a constant boil and the temperature is continuously monitored. As the solution boils the component with the lower boiling point will vaporize first and condense into the collected fraction accordingly. It is this difference in boiling points that allows for the different molecules to be isolated (2).

Fractional distillations are set up very similarly to simple distillations, however there is

added a fractioning column. During this experiment the fractioning column was filled with a copper mesh (1). This method is much more effective at isolating the components of a solution due to this fractioning column. The purpose of the column is to increase the surface area. Once the vapors begin to rise into the column they come into contact with the mesh and they condensate and run back down to the solution. This allows for an increased volatility and once the vapors reach the condenser and are collected as fraction they are very pure (3).

Gas Chromatography allows for the analysis of compounds that can be vaporized with

decomposition (4). In gas chromatography there is a mobile phase, in this case helium which acts

as a carrier. There is also a stationary phase within and around a column (4). The compound to be analyzed interacts with the column and both the mobile and stationary phases. This allows that compound to elute at different rates which dictates retention times. It is these retention times that can be compared to each other as well as to standards (1).

Results: Simple Distillation: Temperatures and Volumes

Vile 1 Total Volume (mL) Temperature ℃ 1.0 61 2.0 65 3.0 69 4.0 72 5.0 73 6.0 74 7.0 74 8.0 74 9.0 75 10.0 76 Vile 3 Total Volume (mL) Temperature ℃ 21.0 80 22.0 80 23.0 80 24.0 80 25.0 81 26.0 81 27.0 81 28.0 82 29.0 82 30.0 83

Vile 2 Total Volume (mL) Temperature ℃ 11.0 77 12.0 76 13.0 76 14.0 76 15.0 77 16.0 78 17.0 78 18.0 77 19.0 79 20.0 79 Vile 4 Total Volume (mL) Temperature ℃ 31.0 83 32.0 83 33.0 83 34.0 83 35.0 83 36.0 83 37.0 83 38.0 83 39.0 83 40.0 83

Fractional Distillation: Temperatures and Volumes

Vile 1 Total Volume (mL) Temperature ℃ 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 21.0 22.0 23.0 24.0 25.0 26.0 27.0 28.0 29.0 30.0 67 68 69 69 70 70 70 70 71 71 77 78 79 80 82 83 85 87 89 91

Vile 2 Total Volume (mL) Temperature ℃ 11.0 12.0 13.0 14.0 15.0 16.0 17.0 18.0 19.0 20.0 31.0 32.0 33.0 34.0 35.0 36.0 37.0 38.0 39.0 40.0 72 72 73 73 74 75 75 75 76 76 92 93 93 93 93 95 92 92 89 76

Vile 3 Total Volume (mL) Temperature ℃

Vile 4 Total Volume (mL) Temperature ℃

Gas Chromatography Analysis:
Distillation Simple Compound 1 n-hexane cyclohexane 2 n-hexane cyclohexane 3 n-hexane cyclohexane 4 n-hexane cyclohexane Area 28948 10791 20753 10608 23323 19763 14827 27484 R.T. 0.886 1.655 0.875 1.645 0.882 1.703 0.879 1.737 Corrected Area 32424.944 10791 23245.643 10608 26124.326 19763 16607.871 27484 % total 75.00% 25.00% 68.70% 31.30% 56.90% 43.10% 37.70% 62.30% Volume (mL) 7.50 2.50 6.87 3.13 5.69 4.31 3.77 6.23 Mol 0.05699 0.02312 0.05220 0.02896 0.04323 0.03985 0.02864 0.05761 0.4972 1.0848 1.8025 Mol Frac. A/B 2.465

Fractional Compound 1 n-hexane cyclohexane 2 n-hexane
Show More

Related Documents: Essay on Adsorption Chromatography

Study Guide: HPLC Methodologies Essay

principle for separation in normal phase, reversed phase, ion-exchange and gel permeation chromatography? Normal and Reversed Phase Chromatography What is the relationship between polarity of the mobile phase vs. elution time and resolution in normal phase and reversed phase chromatography? Study slide 6 very carefully that illustrates that the use of stronger mobile phase in normal and reversed phase chromatography decrease run time but also decrease resolution and vice versa. You should be able to…

Words 917 - Pages 4

Journal Of Chromatographic Science Vol 41 Essay examples

35-959 Rzeszów, Poland Abstract The influence of mobile phase composition on the retention of selected test analytes in different normal- and reversed-phase chromatographic systems is studied. A novel adsorption model for an accurate prediction of the analyte retention in the column chromatography with binary mobile phase is proposed. Performance of the model is compared with the retention model reported in the literature. Both models are verified for different HPLC systems by use of three criteria:…

Words 2710 - Pages 11

How To Form Co And Sources

zone& flame zone 44. Effect 45. Reduction 46. FGD 47. Measurement and monitoring what 48. Method of sampling methods 49. Wet chemistry 50. Spectroscopy 51. Chemiluminescence 52. Electrochemistry 53. Chromatography 54. Mass spectrometry 55. Atomic Spectroscopy 56. Method of stack emission monitoring(2) 57. Factor influencing choice 58. NOx/SOx discussion (what teh chemisty involved , advantage and disavantages of each methods, effencies…

Words 566 - Pages 3

Chromatography Lab Report

INTRODUCTION CHROMATOGRAPHY Chromatography was originally developed in the year 1903 by the Russian botanist Michael Tswett in percolating a petroleum ether extract through a glass column packed with powered calcium carbonate for the separation of colored pigments. Elution means a chromatographic separation involves the placing of the sample into a liquid or solid stationary phase and passing a liquid or gaseous mobile phase through or over it. Whether…

Words 955 - Pages 4

Expt2 Spinach Chromatograhy W15 Essay

CHEM 2120 Experiment 2 Column Chromatography of a Spinach Extract Index Objectives Experimental Procedure Introduction Write-up Prelab Preparation References Objectives i. To learn the technique of column chromatography. ii. To learn how molecular polarity determines both the solubility and the relative column migration rates (Rf) of different compounds. iii. To determinethe relative polarity and colours of chlorophylls versus carotenoids. Introduction Organic chemists use a variety…

Words 3643 - Pages 15

Sophorolipids Case Study

Sophorolipids are well known for their surface active potential in various industrial and household applications. They are utilized in laundry detergents (Hall et al. 1996), food industry (Akari and Akari 1987), cold storage transportation (Masaru et al. 2001), Bioremediation (Mulligan et al. 2001), cosmetic and dermatological products (Morya et al.2013), plant protection ((Kim et al. 2002), medical application as anticancer agent (Fu et al. (2008), anti-inflammatory or antiallergy agents (Hagler…

Words 996 - Pages 4

Essay on Professional Athletes and Steroids

A steroid is a type of organic compound that contains a characteristic arrangement of four cycloalkane rings joined to one another. Examples of steroids include the dietary lipid cholesterol, the sex hormones estradiol and testosterone,[1]:10–19 bile acids, and drugs such as the anti-inflammatory agent dexamethasone.[2] The steroid core is composed of seventeen carbon atoms bonded together in the form of four fused rings: three cyclohexane rings (designated as rings A, B and C in the figure to…

Words 2968 - Pages 12