Week 4: Polarimetry Flashcards
What is polarimetry?
Polarimetry is the measurement of the polarization of light.
True or False: Polarimetry can be used to determine the concentration of chiral compounds.
True
Fill in the blank: The instrument used to measure the angle of rotation of polarized light is called a __________.
polarimeter
What is the significance of optical activity in polarimetry?
Optical activity refers to the ability of chiral substances to rotate the plane of polarized light.
Which type of light is used in polarimetry?
Monochromatic light
What is the unit of measurement for optical rotation?
Degrees
True or False: Both enantiomers of a chiral compound rotate polarized light in the same direction.
False
What does a polarimeter measure?
A polarimeter measures the angle of rotation of polarized light as it passes through a sample.
Multiple Choice: Which of the following substances is typically analyzed using polarimetry? A) Water B) Sugar C) Salt D) Oil
B) Sugar
What is the relationship between concentration and optical rotation in polarimetry?
The optical rotation is directly proportional to the concentration of the chiral substance.
Fill in the blank: The __________ of a substance is defined as the specific rotation divided by the concentration.
optical purity
True or False: Polarimetry can only be used for liquid samples.
False
What type of molecules are primarily studied using polarimetry?
Chiral molecules
What is specific rotation?
Specific rotation is the observed rotation of light divided by the path length and concentration of the solution.
Multiple Choice: The specific rotation of a compound is influenced by: A) Temperature B) Wavelength of light C) Concentration D) All of the above
D) All of the above
What is the role of a polarizer in a polarimeter?
A polarizer allows only light waves of a specific polarization to pass through.
True or False: The plane of polarized light can be rotated by passing it through a non-chiral substance.
False
What is the maximum angle of rotation for a solution in polarimetry?
The maximum angle of rotation depends on the specific compound and its concentration.
Fill in the blank: The __________ is the angle at which the light is rotated when it exits the sample tube.
exit angle
What does a negative optical rotation indicate?
A negative optical rotation indicates that the substance rotates polarized light in the opposite direction.
Multiple Choice: Which of the following can affect the results of polarimetry? A) Sample impurities B) Temperature variations C) Light wavelength D) All of the above
D) All of the above
What is the purpose of a compensator in polarimetry?
A compensator is used to enhance the sensitivity of the measurement by compensating for the optical rotation.
True or False: The principle of polarimetry is based on the interaction of light with matter.
True
What is the main advantage of using polarimetry in analytical chemistry?
Polarimetry is a non-destructive method that can provide information about chiral purity and concentration.
