A thermodynamically spontaneous reaction occurs without the need for external energy input under given conditions, meaning it has a negative Gibbs free energy (ΔG < 0).
In the complex [ 𝐹 𝑒 ( 𝑁 𝐻 3 ) 6 ] ^2 + , iron (Fe) is in the +2 oxidation state, meaning it has a 𝑑6 electron configuration.
Ammonia (NH₃) is considered a strong field ligand under Crystal Field Theory (CFT), causing the electrons in the 𝑑-orbitals to pair up due to the large splitting of the
𝑑-orbitals.
In a strong field environment, the electrons occupy the lower energy 𝑡2𝑔 orbitals first, and all six electrons pair up, leaving no unpaired electrons.
The Tyndall effect is the scattering of light by particles in a colloid or in very fine suspensions.
When light passes through a colloidal solution, the dispersed particles scatter the light in different directions, making the path of the light visible.