Transition Elements Flashcards
What is the electron configuration of chromium after 3p6?
4s1 3d5
Define transition element
A d-block element that forms an ion with an incomplete d sub-shell
What properties do transition metals have? Give examples
Variable oxidation states eg Cu2+ and Cu3+ Form coloured ions Eg Fe2+ ions are pale green, Fe3+ ions are yellow Very effective catalysts Eg iron is used in the Haber process for making ammonia Form complex ions Eg [Fe(H2O)6]3+
Reaction of Cu2+ with NaOH
Cu2+(aq) + 2OH-(aq) –> Cu(OH)2(s)
Reaction of Co2+ and NaOH
Co2+(aq) + 2OH-(aq) –> Co(OH)2(s)
Reaction of Fe2+ with NaOH
Fe2+(aq) + 2OH-(aq) –> Fe(OH)2(s)
Reaction of Fe3+ with NaOH
Fe3+(aq) + 3OH-(aq) –> Fe(OH)3(s)
Define ligand
A molecule or ion that can donate a pair of electrons to the transition metal ion to form a coordinate bond
Define complex ion
A transition metal ion bonded to one or more ligand by coordinate bonds
Define coordination number
The total number of coordinate bonds formed between a central metal ion and its ligands
Give the formula and charge of the ligands thiocyanate
:SCN-
Give the formula and charge of a cyanide ligand
:CN-
Give 2 examples of complex ions with an octahedral shape
[Fe(H2O)6]2+
[Cu(H2O)6]2+
What is a bidentate ligand?
A ligand that can donate 2 pairs of electrons to the central metal ion to form 2 coordinate bonds
Eg ‘en’
Define stereoisomerism
Compounds with the same structural formula but with a different arrangement of atoms in space
Which combinations of ligands can form cis-trans isomers?
Square planar: 2 monodentate of the same type, 2 monodentate of another type
Octahedral: 2 monodentate, 2 bidentate
Octahedral: 2 monodentate of one type, 4 monodentate of another type