Transition Metals - General Properties

Transition metals have variable oxidation states:

• V: +2; +3; +4; +5
• Cr: +3; +6
• Mn: +2; +4; +7
• Fe: +2; +3
• Co: +2; +3
• Ni: +2
• Cu: +1; +2

Transition metals act as heterogeneous catalysts. Transition metal ions in solution can act as homogeneous catalysts. In particular learn:

Iron in the Haber Process

Vanadium (v) Oxide in the Contact Process

Nickel in hydrogenation reactions

Platinum/Rhodium in catalytic oxidation of ammonia

• Good conductor of electricity and have high densities
• Many transition metals form coloured complexes
• Transition metal ions in aqueous solution are often coloured.
• Aqueous transition metal ions are actually hexaaqua cations e.g. Ni²⁺ is actually [Ni(H₂O)₆]²⁺

• The 3d fills after the 4s

• The atoms of Cr and Cu are unusual:

-  Cr atom is 1s², 2s², 2p⁶, 3s², 3p⁶, 3d⁵, 4s¹

- Cu atom is 1s², 2s², 2p⁶, 3s², 3p⁶, 3d¹⁰, 4s¹

• The first series of transition metal atoms lose their 4s electrons first when forming ions.