General properties of transition metalsAQA A-Level Chemistry: Mind map

Exam questions on General properties of transition metals

1. A student is comparing the electronic structures of some d-block elements. Iron has the configuration [Ar]3d⁶4s², scandium [Ar]3d¹4s², zinc [Ar]3d¹⁰4s² and copper [Ar]3d¹⁰4s¹.
   Explain why zinc is not classified as a transition metal even though it is a d-block element.2 marks
2. Cobalt(II) chloride dissolves in water to give the pink complex ion [Co(H₂O)₆]²⁺. Adding excess ammonia solution forms [Co(NH₃)₆]²⁺, and adding concentrated hydrochloric acid forms the blue complex ion [CoCl₄]²⁻.
   Ammonia, NH₃, can act as a ligand but the ammonium ion, NH₄⁺, cannot. Explain why.2 marks
3. Solid iron(II) sulfate dissolves in water to give a pale green solution containing [Fe(H₂O)₆]²⁺. On standing in air the solution slowly turns yellow-brown as iron(III) ions form. Finely divided iron is used as the catalyst in the Haber process.
   Identify three characteristic properties of transition metals that are shown by the information, quoting the evidence for each.3 marks