d and f BLOCK ELEMENTS

Why does copper have a positive E°(M2+/M) value?

• Its low atomization enthalpy is balanced by its high hydration enthalpy.
• Its high atomization enthalpy is sufficiently balanced by its hydration enthalpy.
• Its low atomization enthalpy is not balanced by its hydration enthalpy.
• Its high atomization enthalpy is not sufficiently balanced by its hydration enthalpy.

Which of the following elements shows the least number of oxidation states?

• Iron
• Copper
• Vanadium
• Zinc

What is the oxidation state of Vanadium in VOCl₂?

• +2
• +3
• +4
• +5

Why is the zero oxidation state possible for metals in complexes like Ni(CO)₄?

• Metals are not oxidized
• Ligands provide electrons
• Stabilization by π-acceptor ligands
• The complexes are ionic

What is the oxidation state of Cobalt in Co₂O₃?

• +1
• +2
• +3
• +4