Chemistry of the D block Flashcards
Define a transition metal
Must form at least one stable ion with a partly filled d orbital
In what complexes do transition metals form ions
Tetrahedral and octahedral
What oxidation states do the following form: Cr Mn Fe Co Cu
Cr - III & II Mn - VII Fe - III & II Co - III Cu - I & II
What colour are the following in solution: Cr3+ CrO4 Cr2O7 Cu2+ Fe2+ Co2+ MnO4- Fe3+
Cr3+ - green CrO4 - green-yellow Cr2O7 - orange Cu2+ - blue Fe2+ - green Co2+ - pink MnO4- - purple Fe3+ - yellow
How is colour formed in transition metal compounds
When a ligand binds to the metal cation it displaces the d orbital, promoting some of them to a higher energy level. The gap between the two sets of orbitals determines the colour. Which ever frequencies of light are not absorbed show as colours.
What factors affect the frequencies of light absorbed by transition metal compounds
the metal cation
the ligand identity
the charge on the cation
What is shown by ZLAT OH compounds
Redissolving precipitate in excess OH
Describe ligand exchange
1 or more ligand being replaced by another in a compound
Name the properties of transition metals
Catalytic
Colours
Variable oxidation states
Form complex ions
How is nickel used as a catalyst
in the hydrogenation of alkenes
How is iron used as a catalyst
Haber process
How is vanadium oxide used as catalyst
contact process
How is manganese oxide used as a catalyst
decomposition of hydrogen peroxide
