Test: Optical Isomerism Polarimetry - JEE MCQ

The correct answer is Option C.
As it propagates, both magnitude of electric vector and direction of polarization varies.

The correct answer is Option C.
For a pure enantiomer, signs of specific rotation and its magnitude are fundamental properties as they do not depend on concentration of sample or length of sample tube.

Optical purity = optical rotation of mixture/optical rotation of pure compound . 
(mixture) [α]_D²⁵  = +6.76°
+[α]D = +13.57°
Since rotation of two enantiomers cancel each other, so rotation is due to enantiomeric excess.
Enantiomeric excess = observed specific rotation/max. Specific rotation = 6.76/13.52×100
= 50%
Therefore, %age of each enantiomer is given by, 
If we have (+) (-) mixture(+) is in excess,
 %(+) = ee/2 + 50%
= 75 % (s)
%(-) = 25% (s)

The correct answer is Option C.
The specific rotation of a molecule is the rotation in degrees observed upon passing polarized light through a path length of 1 decimetre (dm) at a concentration of 1 g/mL. Specific rotation is almost always reported along with the temperature, wavelength of light used, the solvent, and the concentration, since it is sensitive to these factors as well.
Magnitude of specific rotation depends on temperature. However, it does not depend on concentration, purity or length of sample tude.

The correct answer is Option C.

A meso compound is optically inactive with zero specific rotation.

Where [α] = measured rotation, [α]sp = specific rotation, l = length of tube (in decimeter)

Enantiomers are chiral molecules that are mirror images of one another. Furthermore, the molecules are non-superimposable on one another. This means that the molecules cannot be placed on top of one another and give the same molecule. Chiral molecules with one or more stereocenters can be enantiomers.

Specific rotation ([α]) is a property of a chiral chemical compound. It is defined as the change in orientation of monochromatic plane-polarized light, per unit distance–concentration product, as the light passes through a sample of a compound in solution.

For an optically active substance, defined by [α]θλ = α/γl, where α is the angle through which plane polarized light is rotated by a solution of mass concentration γ and path length l. Here θ is the Celsius temperature and λ the wavelength of the light at which the measurement is carried out.
Values for specific rotation are reported in units of deg·mL·g⁻¹·dm⁻¹, which are typically shortened to just degrees, wherein the other components of the unit are tacitly assumed.[4] These values should always be accompanied by information about the temperature, solvent and wavelength of light used, as all of these variables can affect the specific rotation. As noted above, temperature and wavelength are frequently reported as a superscript and subscript, respectively, while the solvent is reported parenthetically, or omitted if it happens to be water.

Option A, B and C are correct. For this case, there are 3 possibilities. Either the solution is itself laboratory, or its laevo + dextro with laevo in excess so that we have rotation of light in -. If B is true, then option c is also true. As (+) and (-) are two optical compounds that are not isomers. However, Option D is incorrect as optical rotation is independent of configuration of molecule.

The correct options are a, b, d

Enantiomers are mirror images of each other so they have the opposite configuration at the stereocentre and they can be separated by chromatographic method if separation

The correct options are a, b

Interchanging two groups about the chiral centre changes the configuration of the compound