d and f BLOCK ELEMENTS

Which of the following is an example of a disproportionation reaction involving a transition metal?

• Zn + Cu2+ → Zn2+ + Cu
• 2Fe3+ + Sn2+ → 2Fe2+ + Sn4+
• 3MnO42- + 4H+ → 2MnO4- + MnO2 + 2H2O
• Cr2O72- + 6Fe2+ + 14H+ → 2Cr3+ + 6Fe3+ + 7H2O

Which of the following statements best describes the term 'disproportionation' in the context of redox reactions?

• Two different species are oxidized.
• Two different species are reduced.
• A single species is simultaneously oxidized and reduced.
• Oxidation and reduction occur in separate molecules.

What is a key chemical difference between Lanthanoids and Actinoids regarding their reactivity with water?

• Lanthanoids react more vigorously.
• They react identically.
• Actinoids generally react more vigorously with water than Lanthanoids.
• Reactivity depends only on the specific element.

What is the typical colour of an aqueous solution containing Nd3+ ions?

• Green
• Yellow
• Blue
• Purple/Pink

What is the typical colour of an aqueous solution containing Eu3+ ions?

• Green
• Blue
• Pale pink
• Colourless