Transition metals Flashcards
What are the d-block transition metals?
The d-block transition metals are metals with an incomplete d
subshell in at least one of their ions.
The filling of the d orbitals follows?
The aufbau principle, with the
exception of chromium and copper atoms
Why do chromium and copper atoms not follow the d orbital filling with the aufbau principle?
These exceptions are due to the special stability associated with the d subshell being half-filled or completely filled.
When atoms from the first row of the transition elements form ions what electrons do they loose first?
When atoms from the first row of the transition elements form ions, it is the 4s electrons that are lost first rather than the 3d electrons.
An element is said to be in a particular oxidation state when it has?
A specific oxidation number.
The oxidation number can be determined by?
- uncombined elements have an oxidation number of 0
- ions containing single atoms have an oxidation number that is the
same as the charge on the ion - in most of its compounds, oxygen has an oxidation number of −2
- in most of its compounds, hydrogen has an oxidation number of
+1 - the sum of all the oxidation numbers of all the atoms in a neutral
compound must add up to zero - the sum of all the oxidation numbers of all the atoms in a
polyatomic ion must be equal to the charge on the ion
A transition metal can have different oxidation states in its
compounds. This means that
compounds of the same transition metal in different oxidation states may have different?
Colours
What can oxidation and reduction be defined as?
Oxidation can be defined as an increase in oxidation number.
Reduction can be considered as a decrease in oxidation number.
Compounds containing metals in high oxidation states are often? whereas compounds with metals in low oxidation
states are?
Compounds containing metals in high oxidation states are often
oxidising agents, whereas compounds with metals in low oxidation states are often reducing agents.
Ligands may be?
Negative ions or molecules with non-bonding pairs of
electrons that they donate to the central metal atom or ion, forming dative covalent bonds.
What can ligands be classified as?
Monodentate, bidentate, up to
hexadentate.
The total number of bonds from the ligands to the central transition metal is known as?
The coordination number
Names and formulae can be written according to IUPAC rules for complexes containing?
IN THE NAME:
Ligands are listed first followed by the metal.
If there is more than one type of ligand use the usual prefixes of di, tri etc.
When listing ligands, do so alphabetically (the prefixes don’t count). E.g. pentaammineaqua rather than aquapentaammine
Roman numerals are shown for the oxidation state of the metal e.g. pentaaquahydroxidoiron(III).
IN THE FORMULA:
The complex is enclosed within square brackets.
The metal symbol is written first then the ligands in alphabetical order by symbol e.g. [CoCl4(OH2)2]2- rather than [Co(OH2)2Cl4]2- because C comes before O.
The atom bound to the transition metal should always be listed first where reasonable to do so e.g. [Co(NH3)5(OH2)]3+ rather than Co(NH3)5(H2O)]3+ .
The charge on the complex goes outside the brackets.
BOTH:
- central metals that obey the normal IUPAC rules
- copper (cuprate) and iron (ferrate)
- ligands, including water, ammonia, halogens, cyanide, hydroxide, and oxalate
The oxidation number can be determined using the following?
Uncombined elements have an oxidation number of 0
Ions containing single atoms have an oxidation number that is the same as the charge on the ion
In most of its compounds, oxygen has an oxidation number of -2
In most of its compounds, hydrogen has an oxidation number of +1
The sum of all the oxidation numbers of all the atoms in a molecule or neutral compound must add up to zero.
The sum of all the oxidation numbers of all the atoms in a polyatomic ion must be equal to the charge on the ion.
In a complex of a transition metal, the d orbitals are no longer…
Degenerate
