Question

1. Write the full and noble gas abbreviation electron configuration for the following nickel and cobalt ions:

a. Ni2+ ion

b. Fe3+ ion

2. Write the name of the following coordination complexes, determine the coordination number and the molecular geometry of each complexes:

Complex	Name
[FeF6] 3-
[Fe(C2O4)3]3-
[Fe(NH3)6] 3+

3. Calculate the gap energy in kJ per mole of [Fe(NH₃)₅Cl]²⁺ ion and [Fe(NH₃)₅H₂O]³⁺ ion if the compounds exhibits a maximum absorption at 535 nm and 500 nm respectively.

Answer 1

1) (a) Atomic number of Ni= 28

The electronic configuration of Ni = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁸ 4s²

the noble gas abbreviation of Ni = ₁₈[Ar]3d⁸ 4s² (Argon is the nearest noble gas)

Ni - 2e = Ni²⁺ (the two electron gets away from 4s orbital)

Thus, The electronic configuration of Ni²⁺ = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁸

   the noble gas abbreviation of Ni²⁺ = ₁₈[Ar]3d⁸

(b) Atomic number of Fe = 26

The electronic configuration of Fe = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²  

the noble gas abbreviation of Fe = ₁₈[Ar]3d⁶ 4s² (Argon is the nearest noble gas)

Fe - 3e = Fe³⁺ ( two electron gets away from 4s orbital and one from 3d)

Thus, The electronic configuration of Fe³⁺ = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵

   the noble gas abbreviation of Fe³⁺ = ₁₈[Ar]3d⁵