3.4 Chemistry of the D block Flashcards
What is a transition metal?
A d block element that forms at least one ion with a partially filled d orbital
Why are Cr and Cu exceptions to the electron configuration rules?
As their 4s electron pairs split to give a full and half full 3d orbital instead
What is the electron configuration of Cu2+?
[Ar] 3d 9
Why do transition metals form coloured compounds?`
D orbital splits and electrons move between gaps
energy gaps absorb and release energy causing colour
What are the 2 wavelength equations?
E=hf
F=c/ λ
How do liquids appear coloured?
They transmit coloured light
What is a ligand?
A species with a lone pair of electrons that form a coordinate bond with a transition metal ion
What are four examples of ligands?
NH3
H2O
OH-
Cl-
What 3 factors affect compound colour?
Ligand type
oxidation state
metal ion or element type
What is a complex ion
A species where ligands have formed coordinate binds with t.ms
What are the characteristics of a hydrated ion?
Octahedral
90* and 180*
Bonds steming from Oxygen (4H2Os 2OHs)
coordinate bonds with O
What determines the 2 isomers of hydrated ions?
The position of the OH group
180* between 2 or
90* between the 2
What colour compound does Cu(H2O)6 + OH- form?
Cu(H2O)4(OH)2
Pale blue ppt
What is a ligand exchange?
Solid formed due to a neutral charge
X2+ + 2OH- —->
x(H2O)4(OH)2 + 2 H2O
Fe2+ ligand colour change
Pale green to dirty green
Cu2+ ligand colour change
Blue to Pale blue
Fe3+ ligand colour change
Yellow to Rust brown
Co2+ ligand colour change
Pink to blue
Cr3+ ligand colour change
Green to grey green
Which ligand exchange reaction is amphoteric?
Cr3+ forms [Cr(OH)6]3-
What is the descriptor of transition metal ppts?
Gelatinous
What colour is the NH3 cu ligand?
Royal blue
What colour is the Cl Cu ligand?
Yellow/green
