Chemistry - Equilibria, Energetics and Elements - F325 - Transition Elements (3) Flashcards
Where are the d block elements found?
The d block elements are found between groups 2 and 3.
Transition elements form ions with incomplete of which sub-shell?
Transition elements form ions with incomplete d sub-shells.
Which two transition metals actually do not form ions with partially filled d sub-shells?
Scandium and zinc, the first and last members of this row are not actually classed as transition metals because they do not have any ions with partially filled d orbitals.
Transition metals have ……….. densities.
Transition metals have high densities.
Transition metals have ……… melting and boiling points.
Transition metals have high melting and boiling points.
Which electrons are usually lost first, the 3d or 4s electrons?
The 4s electrons are usually lost first because they occupy a higher energy level than the 3d electrons.
Define a catalyst.
A catalyst is a substance that increases the rate of reaction by providing an alternative route for the reaction to follow
What is used as the catalyst in the Haber process?
Iron is used as the catalyst in the Haber process.
What is used as the catalyst in the contact process?
Vanadium (V) oxide is used as the catalyst in the contact process.
In the hydrogenation of alkenes, what is used as the catalyst?
In the hydrogenation of alkenes, a nickel metal catalyst is used to lower the temperature and pressure required to carry out the reaction.
What is used as the catalyst in the decomposition of hydrogen peroxide into water and oxygen?
Manganese oxide is used as the catalyst in the decomposition of hydrogen peroxide into water and oxygen.
Define a precipitation reaction.
A precipitation reaction is one in which soluble ions, in separate solutions, are mixed together to produce an insoluble compound.
Define a complex ion.
A complex ion is a transition metal ion bonded to one or more ligands by coordinate bonds (dative covalent bonds).
Define a ligand.
A ligand is a molecule or ion that can donate a pair of electrons to the transition metal ion to form a coordinate bond.
What is the coordination number?
The coordination number is the total number of coordinate bonds formed between a central metal ion and its ligands.
What is a monodentate ligand?
A monodentate ligand is one that donates just one pair of electrons to the central metal ion to form one coordinate bond.
What is the most common shape of complex ions?
Octahedral is the most common shape of complex ions.
Define stereoisomers.
Stereoisomers are species with the same structural formula but with a different arrangement of the atoms in space.
What is a bidentate ligand?
Bidentate ligands can donae two lone pairs of electrons to the central metal ion to form two coordinate bonds.
Which types of complex ions can show cis-trans isomerism?
Octahedral complexes containing bidentate ligands can show cis-trans isomerism.
What is a hexadentate ligand?
A hexadentate ligand has six lone pairs of electrons, each forming a coordinate bond to a metal ion in a complex ion.
What is ligand substitution?
Ligand substitution is a reaction in which one ligand in a complex ion is replaced by another ligand.
Haemoglobin consists of how many polypeptide chains?
Haemoglobin consists of four polypeptide chains.
What are the polypeptide chains in haemoglobin?
The polypeptide chains are haem groups.
What does each haem group have at its centre?
Each haem group has Fe2+ at its centre.
What can the Fe2+ at the centre of each haem group do?
Each haem group has Fe2+ at its centre which can bind oxygen.
How many coordinate bonds are there between the Fe2+ and the nitrogen in the haem structure?
There are four coordinate bonds between the Fe2+ ion and the nitrogen in the haem structure.
Fe2+ forms coordinate bonds with what?
Four coordinate bonds with nitrogen.
A coordinate bond with the protein globin
And a coordinate bond to an oxygen molecule.
TRUE or FALSE
The binding of carbon monoxide to haemoglobin is reversible.
FALSE!
The binding of carbon monoxide to haemoglobin is irreversible.
How is carbon monoxide formed?
Carbon monoxide is formed from the incomplete combustion of carbon containing fuels.
Define the stability constant.
The stability constant, Kstab, is the equilibrium constant for an equilibrium existing between a transition metal ion surrounded by water ligands and the complex formed when the same ion has undergone ligand substitution.
