d and f BLOCK ELEMENTS

What role does hydration enthalpy play in determining copper's positive E°(M2+/M) value, according to the text?

• Its high hydration enthalpy perfectly balances the high energy costs.
• Its hydration enthalpy is the only factor considered.
• Its high hydration enthalpy makes the E° value more negative.
• Its relatively low hydration enthalpy fails to adequately compensate for the high energy costs of atomization and ionization.

What is the primary reason, according to the text, for the stability gained when Mn3+ (d4) is reduced to Mn2+ (d5)?

• Achieving a fully filled d subshell.
• Achieving a half-filled t2g level.
• Pairing of electrons in the eg level.
• Achieving a half-filled d subshell in the d5 configuration.

What is the primary reason, according to the text, for the stability gained when Cr2+ (d4) is oxidized to Cr3+ (d3)?

• Achieving a fully filled d subshell.
• Achieving a half-filled d subshell.
• Pairing of electrons in the eg level.
• Achieving a half-filled t2g level in the d3 configuration.

How does the text explain the relationship between a metal's E°(M2+/M) value and its ability to liberate H2 from acids?

• Metals with positive E° values can liberate H2, while those with negative E° values generally cannot.
• There is no relationship between E° and the ability to liberate H2.
• Only the hydration enthalpy determines the ability to liberate H2.
• Metals with negative E° values can liberate H2, while those with positive E° values generally cannot.

What does the text suggest is the primary energy factor that makes the transformation of Cu(s) to Cu2+(aq) energetically demanding?

• Its high first ionization enthalpy.
• Its high second ionization enthalpy.
• Its low hydration enthalpy.
• Its high atomization enthalpy.