Question

In ${{[Cr{{({{C}_{2}}{{O}_{4}})}_{3}}]}^{3-}}$, the isomerism shown as:
A. ligand
B. optical
C. geometrical
D. ionization

Answer 1

Hint: Isomerism is the phenomenon in which two or more compounds have the same molecular formula but different arrangement of atoms. These also differ in physical and chemical properties with each other.

Complete step-by-step answer: The compounds following the isomerism phenomenon are known as isomers and the word isomer is made up from two Greek words isos and meros where isos means same or meros means equal parts. Isomerism is further divided into two types called structural isomerism and stereoisomerism.
Structural isomerism is also known as constitutional isomerism in which the functional groups and the atoms in the molecules are linked in different ways whereas stereoisomerism is arises in those compounds which have the same chemical formula but different orientations of the atoms belonging to the molecules present in 3-D i.e. three-dimensional space. Geometric isomerism consists of two types called geometric and optical isomerism.
Compound given shows optical isomerism in which compounds have similar type of bonds but different spatial arrangements of atoms which forms non-superimposable mirror images i.e. optically active in nature and these optical isomers are also known as enantiomers.

Hence in ${{[Cr{{({{C}_{2}}{{O}_{4}})}_{3}}]}^{3-}}$, the isomerism shown is optical, option B is correct

Note: Enantiomers differ from each other in their optical activities i.e. if enantiomers rotate the plane of polarized light to the right then it is known as dextro rotatory represented by symbol d or (+) whereas in left it is known as laevo rotatory represented by l or (-).