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Characterization B - Coggle Diagram

- - - - Sample is analyzed relatively quickly
      - Only a small sample is required
      - Highly accurate and precise
    - - Lower column efficiency than that of capillary columns
      - Signal noise or impurities present in extremely small amounts can appear on the GC chart
- - - - Once the components are done flowing through the plate, the solvent spots are marked and the Rf values are then calculated. Rf values tell how far the solvent traveled and help tell what compounds are present.
  - - - 1) TLC is fast, easy, and cheap (making it one of the most common analytical techniques used in organic chemistry lab)
        2) TLC has a high degree of accuracy and precision for instrumental TLC
        3) Only a small sample size is required
    - - 1) Some reaction products may not have a known sample against which a comparison can be made
        2) It is often not used to determine the identity of an unknown because many molecules can have the same Rf value (only qualitative analysis is possible, not quantitative)
        3) only soluble components of the mixture are possible
- - - - Video showing procedure. Note: Not the same chemicals
  - - - Exception:
        
        Eutectic Mixture: A specific composition of two compounds, which melts at a depressed but sharp narrow melting point range
        
        Eutectic Point: Temp. at which Eutectic mixture melts.
- - - - Pros
        
        Sample can be recovered and reused.
        
        Produces high precision results.
        
        NMR is reproducible.
      - Cons
        
        Has trouble with molecules that have a high molecular weight.
        
        Requires expensive equipment.
        
        Not very sensitive
    - - Nuclear Magnetic Resonance (NMR) analyzes different protons within a molecule by placing the molecule inside a strong magnet while being irradiated with radio-wave photons. Hydrogen nuclei within the molecule absorb the photons based on the electron density surrounding their nucleus. The energy of the radio wave tells us about the characteristics of the proton nucleus.
      - NMR is used on molecules to determine their purity along with their molecular structure.
      - The area under the curve on an NMR spectroscopy graph tells us how many protons are present at that energy level.