d and f BLOCK ELEMENTS

What is the expected E°(M2+/M) behavior for elements just before and just after an element with a stable d5 or d10 M2+ configuration (e.g., Cr, Mn, Zn)?

• They will all follow the exact same trend.
• They will all have identical E° values.
• They will have less negative E° values than the general trend.
• The elements just before might have less negative E° values, and those just after might have more negative E° values than the general trend.

How does the Jahn-Teller effect potentially influence the hydration enthalpy of Cu2+ (d9)?

• It makes the ion perfectly spherical.
• It prevents hydration from occurring.
• It only affects the color, not the enthalpy.
• It causes a distortion in the hydrated ion's geometry, affecting the crystal field stabilization energy and thus the hydration enthalpy.

What is the primary driving force for the reaction between copper and nitric acid?

• The low E° value of the Cu2+/Cu couple.
• The formation of a gas.
• The high concentration of nitric acid.
• The high positive E° value of the nitric acid reduction couple makes the overall cell potential positive.

If a new transition metal element were discovered with a d7 electronic configuration for its M2+ ion, how might its E°(M2+/M) value compare to its neighbors, assuming no other special stability?

• It would definitely have a more negative E° value.
• It would definitely have a more positive E° value.
• It would be impossible to predict.
• It would likely follow the general trend based on ionization enthalpies.

Which of the following best explains why the E°(M2+/M) value for Mn is more negative than expected from the general trend?

• Its low atomic number.
• Its high hydration enthalpy.
• Its low ionization enthalpies.
• The extra stability associated with the d5 configuration of Mn2+.