Transition metals Flashcards
define the term transition metal
element in the d bock that forms a stable ion with a partially filled d subshell
what are some unique chemical properties of transition metals
form complexes
form coloured ions in solution
variable oxidation states
good catalysts
why do transition metals have varying oxidation states
4s and 3d orbitals are close in energy levels so electrons can be lost from both and remaining electrons can form stable configurations
what is unique about chromium and copper
does not follow the rule that the 4s subshell is filled before the 3d subshell
define the term ligand
a molecule or ion with a lone pair of electrons that is able to form a dative covalent bond to the central metal ion by donation of this electron pair
give three examples of common ligands
Cl-, H2O, NH3
what does monodentate mean and give some examples
ligands that form one coordinate bond (H2O, Cl-, NH3)
what does bidentate mean and give an example
ligands that form two coordinate bonds (NH2CH2CH2NH2)
what is the term for ligands that form multiple coordinate bonds
multidentate
what is a coordination number
the total number of coordinate bonds formed with the central metal ion
describe and octahedral complex and give some examples
complexes containing H2O and NH3
bond angle 90
usually six-fold coordination
Describe a tetrahedral complex and give some examples
when complexes form with larger ligands such as Cl-
bond angle 109.5
4 ligands coordinated
can show optical isomerism
describe a square planar complex and give an example
platinum and nickel form square planar shape
consists of four coordinate bonds
bond angle 90
draw a molecule of cisplatin
where can optical isomerism be found in complex ion molecules
seen in some octahedral molecules with bidentate ligands, have non-superimposable mirror images of each other
draw the ligand substitutions for copper reacting with Cl- and NH3
describe the structure of haem
example of a multidentate ligand
central Fe2+ion
a ligand substitution reaction occurs when the oxygen bound to haem is replaced with carbon monoxide
what does Cr3+ form when it reacts with NaOH as a metal-aqua ion and with OH-
metal-aqua- violet solution
OH-= green precipitate
what does Fe 3+ form when it reacts with NaOH as a metal aqua ion and with OH-
metal aqua- yellow solution
OH-= brown precipitate
what Fe2+ form when it reacts with NaOH as a metal-aqua ion and with OH-
metal aqua- green solution
OH-= green precipitate
