Sign In | Subscribe

Enter your Sign on user name and password.

Forgot password?
  • Follow us on:
Start learning today, and be successful in your academic & professional career. Start Today!
Loading video...
This is a quick preview of the lesson. For full access, please Log In or Sign up.
For more information, please see full course syllabus of Organic Chemistry
  • Discussion

  • Download Lecture Slides

  • Table of Contents

  • Related Books & Services

Bookmark and Share
Lecture Comments (2)

1 answer

Last reply by: Professor Starkey
Thu Mar 31, 2016 2:08 PM

Post by Tammy T on March 31, 2016

Why Silica gel SiO2 is polar? I drew out Lewis structure and VSEPR of SiO2, and the 2 dipole moments toward the 2 O on SiO2 molecule cancelled each other out. I thought SiO2 molecule has no net dipole moment overall. Please explain. Thank you great lecture!!

Introduction to TLC (Thin-Layer Chromatography)

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

  • Intro 0:00
  • Chromatography 0:06
    • Purification & Analysis
    • Types of Chromatography: Thin-layer, Column, Gas, & High Performance Liquid
  • Theory of Chromatography 0:44
    • Theory of Chromatography
  • Performing a Thin-layer Chromatography (TLC) Analysis 2:30
    • Overview: Thin-layer Chromatography (TLC) Analysis
  • Step 1: 'Spot' the TLC Plate 4:11
  • Step 2: Prepare the Developing Chamber 5:54
  • Step 3: Develop the TLC Plate 7:30
  • Step 4: Visualize the Spots 9:02
  • Step 5: Calculate the Rf for Each Spot 12:00
  • Compound Polarity: Effect on Rf 16:50
    • Compound Polarity: Effect on Rf
  • Solvent Polarity: Effect on Rf 18:47
    • Solvent Polarity: Effect on Rf
    • Example: EtOAc & Hexane
  • Other Types of Chromatography 22:27
    • Thin-layer Chromatography (TLC)
    • Column Chromatography
    • High Performance Liquid (HPLC)
    • Gas Chromatography (GC)
    • Preparative 'prep' Scale Possible