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Enantiomeric Excess definitions

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  • Optical Activity
    Phenomenon where a substance rotates plane-polarized light, with the direction and degree depending on molecular composition.
  • Enantiomer
    One of a pair of molecules that are non-superimposable mirror images, each causing opposite optical rotations.
  • Specific Rotation
    Measured degree of rotation for a pure sample of a single enantiomer under standard conditions.
  • Racemic Mixture
    Equal parts of two enantiomers, resulting in zero net optical rotation due to complete cancellation.
  • Scalemic Mixture
    Unequal mixture of enantiomers, leading to partial optical activity since cancellation is incomplete.
  • Observed Rotation
    Actual measured rotation of plane-polarized light by a sample, reflecting both composition and concentration.
  • Polarimeter
    Instrument used to measure the angle by which a substance rotates plane-polarized light.
  • Alpha Symbol
    Notation representing observed optical rotation, with or without brackets indicating specific or observed values.
  • Enantiomeric Excess
    Numerical difference in percentage between two enantiomers, indicating the proportion responsible for optical activity.
  • Mirror Image
    Spatial arrangement of atoms that is a non-superimposable reflection, characteristic of enantiomers.
  • Configuration
    Three-dimensional arrangement of atoms in a molecule, determining its optical properties.
  • Sample Tube
    Container in a polarimeter holding the solution whose optical activity is being measured.
  • Cancellation
    Effect where equal and opposite optical rotations from enantiomers result in zero net rotation.