d and f BLOCK ELEMENTS

Which of the following best describes the reaction: 3 MnO4 2– + 4 H+ → 2 MnO4 – + MnO2 + 2H2O?

• It is a simple acid-base reaction
• It is a redox reaction involving only oxidation
• It is a redox reaction involving only reduction
• It is an example of disproportionation

What is one of the main products formed when CrO3 reacts with water?

• HCrO2
• H2CrO4
• Cr(OH)3
• H3CrO3

What is the general trend in the basic character of vanadium oxides as the oxidation number increases from +3 to +5?

• Basic character increases
• Basic character remains constant
• Basic character decreases (V2O3 is basic, V2O5 is amphoteric)
• Basic character first increases then decreases

What is the primary product formed when V2O5 reacts with an acid (like HCl)?

• VO4 3– salts
• VO2 + salts
• V2O4 salts
• VO3 - salts

What is the primary product formed when V2O5 reacts with an alkali (like NaOH)?

• VO2 + salts
• VO4 3– salts
• V2O4 salts
• VO3 - salts