d and f BLOCK ELEMENTS

Which transition metal oxide is basic but its corresponding trioxide is amphoteric?

• CrO and Cr2O3
• Cr2O3 and CrO3
• CrO3 and CrO
• Cr2O3 and CrO2

What is the resulting compound when V2O5 reacts with acids?

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

What physical property is characteristic of Mn2O7?

• It is a yellow crystalline solid
• It is a black powder
• It is a covalent green oil
• It is a white amorphous solid

What is the immediate product when a sodium chromate solution is acidified with sulfuric acid?

• Chromic acid
• Sodium dichromate
• Chromium trioxide
• Sodium chromate precipitate

How is sodium chromate (Na2CrO4) typically prepared for the production of dichromates?

• By heating chromite ore alone
• By reacting chromium metal with sodium hydroxide
• By fusing chromite ore with sodium carbonate in the presence of air
• By electrolyzing a solution of sodium chromate