Final answer:
The number of unpaired electrons in each complex are as follows: [Fe(CN)6]3⁻ with one unpaired electron, [Mn(CN)6]3⁻ with one unpaired electron, [Co(CN)6]3⁻ with no unpaired electrons, and [Ni(CN)6]3⁻ with two unpaired electrons. These counts reflect the strong-field nature of the cyanide ligand which usually results in low spin complexes.
Step-by-step explanation:
The student is asking about the number of unpaired electrons in various transition metal cyanide complexes, which can be determined using crystal field theory and knowing whether the complex is high spin or low spin. The correct number of unpaired electrons for each complex is as follows:
- (a) [Fe(CN)6]3⁻: 1 unpaired electron
- (b) [Mn(CN)6]3⁻: 1 unpaired electron
- (c) [Co(CN)6]3⁻: 0 unpaired electrons
- (d) [Ni(CN)6]3⁻: 2 unpaired electrons
Complexes with cyanide ligands, like these, tend to be low spin because cyanide is a strong-field ligand. The unpaired electron count is pivotal in determining the magnetic properties of the complex, such as whether the complex is paramagnetic (with unpaired electrons) or diamagnetic (with all electrons paired).