d and f BLOCK ELEMENTS

What is the primary reason for the relatively high E°(M2+/M) value for Copper (Cu) compared to other first-row transition metals?

• The stability of the d9 configuration in Cu2+
• The low hydration enthalpy of Cu2+
• The high sum of the first and second ionisation enthalpies of Cu
• Its position at the end of the transition series

Which of the following best explains why Iron (Fe) dissolves readily in dilute mineral acids, unlike Copper (Cu)?

• Fe is harder than Cu
• Fe has a lower melting point than Cu
• Fe has a negative E°(Fe2+/Fe) value, while Cu has a positive E°(Cu2+/Cu) value
• Fe forms more stable oxides than Cu

Why is the E°(M2+/M) value for Chromium (Cr) less negative than expected based on the simple trend across the first transition series?

• The exceptional stability of the d4 configuration in Cr2+
• The contribution of higher ionisation enthalpies outweighs the stability of the d5 configuration
• The low hydration enthalpy of Cr2+
• Its position at the start of the transition series

Why is the formation of high oxidation states possible for transition metals?

• High electronegativity
• Low ionisation enthalpies
• Small atomic radii
• Availability of (n-1)d electrons for bonding

What is the consequence of a large third ionisation enthalpy for an element like Manganese (Mn)?

• It makes the +2 oxidation state more favorable
• It increases the reactivity of Mn metal
• It favors the formation of Mn3+ compounds
• It makes the +3 oxidation state less favorable