d and f BLOCK ELEMENTS

What is the standard electrode potential (E°) for the reduction of Cu²⁺ to Cu?

• -0.25 V
• -0.44 V
• 0.34 V
• -1.18 V

If a new element were discovered and its M2+ ion had a d8 configuration, how might its E°(M2+/M) value compare to its neighbors, based on the text's discussion of deviations?

• It would definitely follow the exact same trend.
• It would definitely have a more negative E° value.
• It would definitely have a more positive E° value.
• Its E° value might deviate from the simple trend if the d8 configuration conferred significant stability.

Why is the comparison in Fig. 4.4 important for understanding transition metal chemistry?

• It proves that thermochemical calculations are useless.
• It shows that all elements follow the same simple rules.
• It confirms that ionization enthalpies are the only important factor.
• It demonstrates that electronic configuration stability significantly influences redox properties beyond simple ionization and hydration energies.

What is the consequence of the extra stability of the d5 configuration for the reducing nature of Fe2+ (d6)?

• Fe2+ becomes a very strong reducing agent by reaching the d5 configuration.
• The d5 configuration makes all d6 ions strong oxidizing agents.
• The d5 configuration has no effect on Fe2+'s reactivity.
• Fe2+ is not a strong reducing agent because losing an electron moves it away from the highly stable d5 configuration of Mn2+.

How does the text's explanation for copper's behavior illustrate the relationship between thermodynamic stability and reactivity?

• Copper's positive E° indicates high thermodynamic stability and high reactivity.
• Thermodynamic stability and reactivity are unrelated.
• Copper's positive E° indicates that Cu2+ ions are unstable.
• Copper's positive E° indicates that the formation of Cu2+(aq) is less thermodynamically favorable, making copper less reactive towards H+ ions.