Which theory explains the colour of transition metal complexes by considering the splitting of d-orbitals in a ligand field?

A. Valence Bond Theory

B. Molecular Orbital Theory

C. Crystal Field Theory

D. Ligand Field Theory

In an octahedral complex, which d-orbitals are raised in energy compared to a tetrahedral complex?

A. dxy, dxz, and dyz

B. dz^2 and dx^2-y^2

C. dx^2 and dy^2

D. All d-orbitals are raised equally

Which of the following is NOT a factor influencing the colour of complexes?

A. The oxidation state of the metal

B. The nature of the ligand

C. The coordination number of the complex

D. The atomic number of the metal

If a complex absorbs light in the blue region of the spectrum, which colour will it most likely appear to the human eye?

A. Blue

B. Green

C. Orange

D. Red

Which type of d-d transition is responsible for the colour in many transition metal complexes?

A. dxy -> dxz

B. dz^2 -> dx^2-y^2

C. dx^2 -> dy^2

D. dxz -> dyz

a) Explain the concept of d-orbital splitting in the context of Crystal Field Theory. How does it relate to the formation of coloured complexes in transition metals? [4]

b) Differentiate between tetrahedral and octahedral complexes in terms of d-orbital splitting. [3]

a) Describe how the observed colour of a complex ion is related to the light it absorbs. [3]

b) Using the complementary colour theory, predict the observed colour of a complex that absorbs green light. [2]

a) How do d-electrons influence the reactivity of transition metal complexes? [3]

b) Explain the factors that can influence the colour of complexes formed by transition metals. [4]

a) Describe the role of d-orbitals in the formation of complex ions in transition metals. [3]

b) Why do some transition metal complexes appear coloured while others are colourless? [3]

c) Explain how the variation in oxidation states of transition metals contributes to their ability to form coloured complexes. [3]

a) What is the significance of Crystal Field Theory in explaining the properties of transition metal complexes? [3]

b) How does the geometry of a complex (tetrahedral vs. octahedral) influence its colour? [4]

c) Describe the industrial applications that exploit the coloured nature of transition metal complexes. [3]