Quiz | The Chemistry of the Transition Metals
Which of the following properties is not a characteristic of transition metal ions?
Form colored solutions
Variable oxidation states
Act as strong acids
Act as catalysts
Transition metal ions can have variable oxidation states (ex: Iron ⇒ Fe2+ and Fe3+)
Transition metal complexes are generally used as catalysts
The 5 d-orbitals of a transition metal ion can be divided into 2 sets: the d electrons can then make a transition by absorbing light ⇒ this explains the color of many coordination compounds
Which of the following statements about [Pt(NH3)2Cl2] is incorrect?
Its name is diamminedichloroplatinum (II)
Its coordination number is 4
It can exhibit cis and trans isomers
None of the above
What is the geometry of [Co(NH3)6]2+?
[Co(NH3)6]2+: 6 NH3 ligands around the central ion Co2+ ⇒ octahedral geometry
The most common geometries are linear (2 ligands), tetrahedral, square planar (4 ligands) and octahedral (6 ligands)
What is the electron configuration of Fe2+ (Fe: Z = 26)?
[Ar] 3d4 4s2
[Ar] 3d5 4s1
[Ar] 3d6 4s2
Iron is an element of the group 8 and has 26 electrons: Fe: [Ar] 3d64s2
In all the chemistry of the transition metals, the 4s orbital behaves as the highest energy orbital compared to 3d orbitals ⇒ Fe2+: [Ar] 3d6
What is the electron configuration of the d-orbitals of [FeF6]4- (high spin)?
Oxidation state of Fe in [FeF6]4-: +2 ⇒ Fe2+: [Ar] 3d6
High-spin configuration: splitting energy Δo < pairing energy ⇒ the d-electrons occupy the eg orbitals before they pair up in the t2g orbitals
Electron configuration of the d-orbitals of [FeF6]4: t2g4 eg2
In which configuration is K4[Fe(CN)6] diamagnetic?
All of the above
Oxidation state of iron in K4[Fe(CN)6]: +2 ⇒ Fe2+: [Ar] 3d6
Low-spin configuration: the electrons first fill the t2g orbitals before occupying the higher-energy eg orbitals ⇒ electron configuration is t2g6 and all electrons are paired ⇒ diamagnetic compound
High-spin configuration: the d-electrons occupy the eg orbitals before they pair up in the t2g orbitals ⇒ electron configuration is t2g4 eg2 and 4 electrons are unpaired ⇒ paramagnetic compound