Complete the exercises below. Determine if each of the following metal complexes is chiral and therefore has an optical isomer: b. octahedral [Ni(en)(NH₃)₄]²⁺.

Chirality refers to the geometric property of a molecule that makes it non-superimposable on its mirror image, much like left and right hands. A chiral molecule typically has an asymmetric carbon atom, but in coordination complexes, chirality can arise from the arrangement of ligands around a central metal atom. Understanding chirality is essential for determining whether a complex can exist in two enantiomeric forms.

Octahedral geometry is a common arrangement in coordination chemistry where a central metal atom is surrounded by six ligands positioned at the corners of an octahedron. This geometry can lead to different spatial arrangements of the ligands, which can affect the chirality of the complex. In the case of [Ni(en)(NH₃)₄]²⁺, the arrangement of the ethylenediamine (en) and ammonia (NH₃) ligands is crucial for assessing its chirality.

Optical isomers, or enantiomers, are pairs of chiral molecules that are mirror images of each other and cannot be superimposed. These isomers have identical physical properties except for their interaction with plane-polarized light, where one will rotate the light in one direction and the other in the opposite direction. Identifying whether a metal complex has optical isomers is important in fields such as pharmaceuticals, where the activity of each enantiomer can differ significantly.