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Characterization Techniques CHEM241-06B - Coggle Diagram
Characterization Techniques CHEM241-06B
Melting Point Analysis
helps determine purity or identity of an organic compound
"sharp/narrow" MP range of 1 degree C for
pure
compounds
"wide/depressed" MP range for
impure
compounds - impurities can affect MP
Efficiency
Strengths
relatively simple and quick technique
requires a small amount of sample
can determine the identity and purity of a compound
Limitations
impurities in compounds make this technique less accurate
difficulty with visually detecting when the sample melts
multiple trials give best results
Additional Resources
https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Book%3A_Physical_Methods_in_Chemistry_and_Nano_Science_(Barron)/02%3A_Physical_and_Thermal_Analysis/2.01%3A_Melting_Point_Analysis
https://www.youtube.com/watch?v=9RNRYLvlbXM&feature=emb_title
use Mel-Temp apparatus
put compound in capillary tube then place in mel-temp
Only applicable for compounds in solid form
Gas Chromatography
https://www.youtube.com/watch?v=UycPljfrnWo
Advantages
Highly efficient, so complex mixtures can be separated in relatively short time
Can be used to accurately measure quantitative data
Tried and true technique with lots of examples and notes available
Disadvantages
Sample must be volatile
Small sample capacity
samples must be soluble and cannot react with the column
How it works and why
Gas Chromatography is commonly used in chemistry for analyzing compounds that can be vaporized.
It can test the purity of of a particular substance or separate a mixture into its base parts.
Thin Layer Chromatography
Procedure
. Create a developing jar for the chromatography plates
Pipet the chromatography plate with one drop and put in the chromatogram. The gel will rise up to a certain distance
After waiting 30 minutes, place the strip under a UV lamp and outline the colored spots
Find the unknown by the using the Rf values. To find the Rf value, divide the distance solvent traveled from the distant spot traveled
Purpose
Use Kf values to find the unknowns of reagents
Advantages
It's efficient and quick
It's cheap
Very simple
Disadvantages
Not the most accurate method
Resources
https://www.youtube.com/watch?v=lj5OWzhZSac
NMR Spectroscopy
Video: Basic Introduction to NMR Spectroscopy
https://www.youtube.com/watch?v=CH-4TtZSvY0
Why NMR?
Nuclei with an odd atomic number have "nuclear spin". The NMR behavior these odd elements are tested because they provide valuable information that can be used to infer the structure of organic compounds.
Advantages
After NMR Spectroscopy, the product can still be used.
Disadvantages
Very big and expensive
purpose
analyze the purity of certain sample