5.3.1 Transition elements Flashcards
What is a d block element?
an element where its highest energy electron is in a d subshell
electron config of copper?
…..3d^5 4s^1
electron config of chromium?
…..3d^10 4s^1
what is a transition element?
d-block elements that have an ion with an incomplete d-subsell
what is the rule when losing electrons?
lose electrons from the 4s subshell first
why are scandium and zinc not transition elements?
They dont hae an ion with an incomplete d-shubshell
what are the 4 properties of transitions metals??
Varitable oxidation states
form coloured ions and compounds
catalysts
they can form complexes
give three examples of transition elements as catalysts
Ni in hydrogenation
Fe in habver process
V2O5 in contact process
what is the bonding in complex ions called?
Dative covalent
what is a complex ion?
A species with ligands linked to a metal ion by dative covalent bonds
what is a ligand
Species which can donate a lone pair of electrons to the metal ion in a complex making a dative covalent bond
what is the coordination number?
The number of dative covalent bonds made by a metal ion in a complex
what in the ion in the centre of a complex ion called?
central metal ion
what are the 3 types of ligands which can form, and what are thier bond angles?
Tetrahedral - 109.5
square planar - 90
Octahedral - 90
what is the order when naming complexes?
what is the negative complex of iron, copper and gold ?
ferrate, cuprate and aurate
what do you add on when its a negative complex?
-ate
name [cucl4]2-
tetrachlorocuprate ii
name [cr(nh3)6]3+
hexaamminechromium iii
hexaaquacobalt ii
[Co(H2O)6]2+
tetrachlorocobaltate ii
[Co(Cl)4]2-
hexaaquacobalt ii + 4cl-
tetrachlorocobaltate ii + 6h2o
what is the colour change of hexaaquacobalt ii to
tetrachlorocobaltate ii
pink to blue
aqueous cobalt chloride with HCl
hexaaquacobalt ii + 4cl- —-> tetrachlorocobaltate ii + 6h2o
what is a ligand substitution?
where a ligand in a complex is replaced by another ligand
what complexes have a tetrahdedral shape?
[CoCl4]2-
[CuCl4]2-
what complexes have a square planar shape?
[Ni(NH3)2Cl2]
[Pt(NH3)2Cl2]
what is a structural isomer?
Molecules with the same molecular formula but a different structural formula
what is a stereoisomer?
compounds with the same structural formula but a different arragement of atoms in 3D space
which side is priority group on?
Cis
Trans
Prioroty group on:
Same side
Opposite sides
which type of complexes can have cis/trans?
Octahedral/square planar w/ only two different kinds of ligands
what is cis platin?
CIS [Pt(NH3)2Cl2]
Its an effective anti cancer drug. It binds to DNA and prevents the DNA from being replicated.
draw cis platin
other than [Ni(NH3)2Cl2] and [Pt(NH3)2Cl2], what other complex has cis-trans isomerism?
[Ni(en)2Cl2]
what is a monodentate ligand?
ligands with one lone pair to form one ddative covalent bond to the central metal ion in a complex
what is a bidentate ligand?
ligands with two lone pair to form two ddative covalent bond to the central metal ion in a complex
give an exmaple of a bidentate ligand
H2NCH2CH2NH2 (en)
what is an optical isomer? Where do they occur?
Stereoisomers that are non-super imposable mirror images of each other.
Formed by octahedral molecules
what is the simple way to draw bidentate ligands?
You draw the molecules with the lone pair and a line between the two
describe ligand substitution with chloride ions
excess HCl is added to [Cu(H2O)6]2+
pale blue to yellow solution (green intermediate)
six H2O moelcuels replaces with 4 cl- ions
[Cu(H2O)6]2+ + 4Cl- ——> ?
[CuCl4]2- + 6H2O
[Cu(H2O)6]2+ + 4Cl——-> [CuCl4]2- + 6H2O colour change
blue -> (green) -> yellow
Draw [Cu(H2O)6]2+
Draw [CuCl4]2-
[Cu(H2O)6]2+ w/ ammonia reaction
(dropwise ammonia) Cu(OH)2 intermediate
(excess) [Cu(H2O)6]2+ + 4NH3 —-> [Cu(NH3)4(H2O)2]2+ + 4H2O
[Cu(H2O)6]2+ w/ ammonia colour change
pale blue -> dark blue
