Chapter 3.7: Optical Activity-How Chirality is Detected in the Laboratory Flashcards
Define optical purity
the specific rotation of a mixture of enantiomers divided by the specific rotation of the enantiomerically pure substance (expressed as a percent). Optical purity is numerically equal to enantiomeric excess, but experimentally determined
What is an instrument for measuring the ability of a compound to rotate the plane of plane-polarized light?
polarimeter
What is the specific rotation of a mixture of enantiomers divided by the specific rotation of the enantiomerically pure substance (expressed as a percent)?
optical purity
What refers to a substance that rotates the plane of polarized light to the right?
dextrorotatory
How does each pair of enantiomers rotate the plane of polarized light?
o Each member of a pair of enantiomers rotates the plane of polarized light in opposite directions
What is the number of degrees through which a compound rotates the plane of polarized light?
observed rotation
Define plane-polarized
light oscillating in only parallel planes
What is the difference between the percentage of two enantiomers in a mixture?
enantiomeric excess
What is a mixture of equal amounts of two enantiomers?
racemic mixtures
the observed rotation of the plane of polarized light when a sample is placed in a tube 1.0 dm in length and at a concentration of 1 g/ml for a solution
specific rotation (α)
Define enantiomeric excess
the difference between the percentage of two enantiomers in a mixture
Define levorotatory
refers to a substance that rotates the plane of polarized light to the left
What is light oscillating in only parallel planes?
plane-polarized
Define specific rotation (α)
the observed rotation of the plane of polarized light when a sample is placed in a tube 1.0 dm in length and at a concentration of 1 g/ml for a solution
Define polarimeter
an instrument for measuring the ability of a compound to rotate the plane of plane-polarized light
