C: Investigate practically a range of reactions involving solutions of transition
metal ions in order to understand the basis for their qualitative analysis.
Transition metals
A transition metal, according to the IUPAC (International union of Pure and applied
chemistry), is any eliment with a partially filled d electron subshell. Transition metals are
the main d-block elements, however, there are f-block elements such as lanthanides and
aclinides which are also transition metals, and this term refers to the elements in group
3 through 12 on the periodic table. Transition metals are the d-block elements,
meanwhile f-block elements (lanthanides and aclinides) are known as the “inner
transition metals”.
Most metals on the periodic table are transition metals. They are placed btween the
groups 2 and 3 on ther periodic table (the central part). They include iron and other
metals that are commonly used in construction, gold and other metals. Their typical
properties, compared to other metals. Are that they have high MP’s, high densities and
can act as catalysts. These are the typical properties, however, some transition metals,
such as mercury, may not show one or more of these properties. Mercury melts at just –
39 degrees celcius, which makes it a liquid at room temperature (BBC Bitesize, n.d.).
Mercury is therefore not classed as a transition metal, regardless of the fact that it
belongs to group 12. This is due to all of its and atoms and and ions being entirely filld
with d-orbitals ie. It has no partly filled d-orbitals in atomic state or its common oxidation
state. However, vanadium, which is classified as a transition metal, due ro its 5 valance
electrons in vanadium that can be lost, has very different properties, attributes, facts and
uses compared to mercury. The first key difference between Mercury and Vandaium is
heir symbol and atomic number. Mercury is represented by the symbol Hg and has an
atomic number of 80 meanwhile vanadium is represnted by the symbol V and has an
atomic number of 23. Another contrast between these two elements is their physical
states. Mercury is a liquid at room temperature whereas vandium is a solid at room
temperature. This links to their melting points as mercury has a melting point of –38.9
degrees celcius and a boiling point of 356.7 degrees celcius, whereas vanadium has a
meltin point of 1890 degrees celcius and a boiling point of 3380 degrees celcius. The
uses of these two elements differ aswell, as mercury is commonly used in
thermometers, dental filling and some electrical components, whereas vanadium is used
in steel production, nuclear reactors and as a catalyst in chemical reactions.
, Figure 01: Periodic table of Vanadium and Mercury
Ligands and complex ions
A metal ion solution cannot exist in isolation and must be in combination with ligands
such as solvent molecules or simple ions, chelating groups, giving rise rot complex ions
or coordination compounds. A ligand is a molecule or ion that donates a lone pair of
electrons to establish a coordinate bond (a covalent bond in which both electrons in the
shared electrons share the same atom) with a transition metal. The number of
coordinate bonds to the core metal atom or ion is the coordination number. There are
three types of ligands: simple, complex and coordinative unsaturation. These complexes
contain a central atom or ion, often a transition metal. The term ligand comes from the
Latin word Ligare (to bind) and was first used by Alfred stock in 1916 in relation to
silicon chemistry. Ligands can be anions, cations or neutral molecules. Ligands can
further be categorized as monodentate (ligand that can only form one coordinate bond),
bidentate (ligand that can coordinate bonds) and multidentate (ligand that can form
multiple coordinate bonds). Water, Ammonia and chloride ions are all examples of
simple ligands.
metal ions in order to understand the basis for their qualitative analysis.
Transition metals
A transition metal, according to the IUPAC (International union of Pure and applied
chemistry), is any eliment with a partially filled d electron subshell. Transition metals are
the main d-block elements, however, there are f-block elements such as lanthanides and
aclinides which are also transition metals, and this term refers to the elements in group
3 through 12 on the periodic table. Transition metals are the d-block elements,
meanwhile f-block elements (lanthanides and aclinides) are known as the “inner
transition metals”.
Most metals on the periodic table are transition metals. They are placed btween the
groups 2 and 3 on ther periodic table (the central part). They include iron and other
metals that are commonly used in construction, gold and other metals. Their typical
properties, compared to other metals. Are that they have high MP’s, high densities and
can act as catalysts. These are the typical properties, however, some transition metals,
such as mercury, may not show one or more of these properties. Mercury melts at just –
39 degrees celcius, which makes it a liquid at room temperature (BBC Bitesize, n.d.).
Mercury is therefore not classed as a transition metal, regardless of the fact that it
belongs to group 12. This is due to all of its and atoms and and ions being entirely filld
with d-orbitals ie. It has no partly filled d-orbitals in atomic state or its common oxidation
state. However, vanadium, which is classified as a transition metal, due ro its 5 valance
electrons in vanadium that can be lost, has very different properties, attributes, facts and
uses compared to mercury. The first key difference between Mercury and Vandaium is
heir symbol and atomic number. Mercury is represented by the symbol Hg and has an
atomic number of 80 meanwhile vanadium is represnted by the symbol V and has an
atomic number of 23. Another contrast between these two elements is their physical
states. Mercury is a liquid at room temperature whereas vandium is a solid at room
temperature. This links to their melting points as mercury has a melting point of –38.9
degrees celcius and a boiling point of 356.7 degrees celcius, whereas vanadium has a
meltin point of 1890 degrees celcius and a boiling point of 3380 degrees celcius. The
uses of these two elements differ aswell, as mercury is commonly used in
thermometers, dental filling and some electrical components, whereas vanadium is used
in steel production, nuclear reactors and as a catalyst in chemical reactions.
, Figure 01: Periodic table of Vanadium and Mercury
Ligands and complex ions
A metal ion solution cannot exist in isolation and must be in combination with ligands
such as solvent molecules or simple ions, chelating groups, giving rise rot complex ions
or coordination compounds. A ligand is a molecule or ion that donates a lone pair of
electrons to establish a coordinate bond (a covalent bond in which both electrons in the
shared electrons share the same atom) with a transition metal. The number of
coordinate bonds to the core metal atom or ion is the coordination number. There are
three types of ligands: simple, complex and coordinative unsaturation. These complexes
contain a central atom or ion, often a transition metal. The term ligand comes from the
Latin word Ligare (to bind) and was first used by Alfred stock in 1916 in relation to
silicon chemistry. Ligands can be anions, cations or neutral molecules. Ligands can
further be categorized as monodentate (ligand that can only form one coordinate bond),
bidentate (ligand that can coordinate bonds) and multidentate (ligand that can form
multiple coordinate bonds). Water, Ammonia and chloride ions are all examples of
simple ligands.
