d and f BLOCK ELEMENTS

What happens when Potassium Dichromate reacts with an iron(II) solution in acidic medium?

• Cr₂O₇²⁻ is oxidized to CrO₄²⁻.
• Cr₂O₇²⁻ is reduced to Cr³⁺, and Fe²⁺ is oxidized to Fe³⁺.
• Cr₂O₇²⁻ precipitates.
• Fe²⁺ reduces Cr₂O₇²⁻ to metallic Cr.

Why is the +2 oxidation state common among transition metals?

• It results in a noble gas configuration.
• It involves the loss of the relatively higher energy 4s electrons.
• It is always the most stable state.
• It requires the least energy overall.

Which of the following is an example of a transition metal catalyst used in industry?

• Sodium in the Solvay process
• Calcium oxide in cement production
• Iron in the Haber process
• Aluminum in electrolysis

What is the usual stable oxidation state of an element with a ground state 3d⁴ configuration?

• +2
• +3 or +4
• +5
• +6

Which of the following is a characteristic property of transition metal complexes?

• They are always diamagnetic.
• They are never colored.
• They often exhibit color.
• They have low melting points.