d and f BLOCK ELEMENTS

Which of the following metal ions is the strongest oxidising agent in aqueous solution based on E°(M3+/M2+) values?

• Cr3+
• Fe3+
• Mn3+
• V3+

Why is the E° value for the Mn3+/Mn2+ couple much more positive than that for Cr3+/Cr2+?

• Similar third ionisation energies
• Much larger third ionisation energy of Mn
• Smaller third ionisation energy of Mn
• More negative hydration energy of Mn3+

What is the primary reason for the irregular E°(M2+/M) values among the first row transition metals?

• Regular atomic radii
• Irregular variation of ionisation enthalpies and sublimation enthalpies
• Constant ionisation enthalpies
• Only variation in hydration enthalpies

What is the formula of the compound formed when Cu2+ oxidises I- according to the text?

• CuI2
• CuI3
• CuI
• Cu(IO3)2

In the reaction 2Cu+ → Cu2+ + Cu, what happens to the Cu+ ions?

• All are oxidised
• All are reduced
• Some are oxidised and some are reduced
• They form a complex