chem topic 15 Flashcards
Definition of a transition metal
d-block element that can form at least 1 stable ions with a partially filled d-subshell
scandium + zinc are not transition metals
Exceptions for electron configs
Chromium- 4s1, 3d4
Copper- 4s1, 3d10
e moves from 4s to 3d to create more stable
Filling and removing electron rules
Filling orbitals - 4s then 3d
Removing electrons- remove from 4s first
Properties of transition metals
Variable oxi states - 4s and 3d energy levels close
coloured ions in solution
good catalysts
Vanadium ion colours in water
V2+ - purple/violet
V3+ - green
VO2+ - blue
VO2 + - yellow
Fe2+ and Fe3+ ions in water
Fe2+ - pale green
Fe3+ - yellow
Cr3+ and Cr2O7 2- ions in water
Cr3+ - green/violet (with 6 water ligands)
Cr2O7 2- - orange
Cu2+ ion colour in water
Blue
Co2+ ion colour in water
pink
Monodente ligand
contains 1 lone pair
e.g H2O, NH3, Cl-
Bidente ligand
2 lone pairs
e.g ethandioate ion
Multidente ligand
More than one coordinate bond
e.g EDTA4- can form 6 co-ord bonds
Meaning of coordination number
no. of coordinate bonds the complex can form
small ligands can fit 6 around CMI (H20 ligands)
larger ligands can only fit 4 (Cl- ligands)
Shape of complex with coord no. of 6
Octahedral
Bond angle- 90
Shape of complex with coord no. of 4
Tetrahedral 109.5 (most)
or
Square planar 90 - only cis-platin (anti-cancer drug)
