d and f BLOCK ELEMENTS

What is the general trend observed for the ionic character of transition metal oxides as the oxidation number increases?

• Ionic character increases
• Ionic character remains constant
• Ionic character decreases then increases
• Ionic character decreases

What is the predominant type of bonding in Mn2O7?

• Ionic
• Metallic
• Covalent
• Hydrogen bonding

What is the main product formed when V2O4 dissolves in acids?

• VO4 3– salts
• VO2+ salts
• V2O5
• VO3 -

What is the main reason Cu+ ion is not stable in aqueous solutions?

• It is highly reactive with water
• It forms insoluble hydroxides
• It undergoes disproportionation
• It is easily oxidized by atmospheric oxygen

What is the definition of 'disproportionation' according to the text?

• A process where an element gains electrons
• A process where an element loses electrons
• A process where a particular oxidation state becomes less stable relative to other oxidation states, one lower, one higher
• A process where two different elements exchange oxidation states