AQA A Level Chemistry 2022 - Paper 3
what colour is {Fe(H2O)6}2+ - Answer pale green
Transition Metal definition - Answer D block elements that form at least one stable ion
with a partially filled d orbital
Classic elements which are not transition metals despite being D-Block elements -
Answer Scandium and Zinc
properties of transition metals which are NOT shared by other metals - Answer -multiple
oxidation states
-coloured ions in solution
-great catalysts
-form complexes with ligands
ligand - Answer a molecule which forms a dative bond with a transition metal
complex ion - Answer A transition metal ion bonded to one or more ligands by
coordinate bonds
co-ordination number - Answer The number of co-ordinate bonds formed to a central
metal ion
What is an example of incomplete ligand substitution? - Answer [Cu(NH3)6]2+ to
[Cu(NH3)4(H2O)2]2+
why does the coordination number not change when substituting water for ammonia ? -
Answer because they are of a similar size
Why does incomplete ligand substitution usually occur? - Answer when substituting
ligands of a different size
Denticity - Answer the number of dative bonds that can be formed with a transition
metal by one ligand
bidentate - Answer When a ligand can form two co-ordinate bonds in a complex ion.
monodentate (or unidentate) - Answer A ligand that can form one bond
Multidentate - Answer A ligand that can form multiple bonds
Chelate effect - Answer the ability of multidentate ligands to form more stable metal
complexes than those formed by similar monodentate ligands
Why is the chelate effect a largely entropic effect? - Answer As you the number of
moles of molecules in the products of the reaction increase. This leads to a large
increase in entropy and this brings the Gibbs free energy below zero for the change.
, AQA A Level Chemistry 2022 - Paper 3
Why is enthalpy change negligible in ligand substitution? - Answer The (dative) bonds
being broken and made are the same strength, amount and type.
Why is carbon monoxide toxic? - Answer CO can from a strong dative bond with
haemoglobin. This is a stronger bond than that made with oxygen and so it replaces the
oxygen attaching to the haemoglobin. This can starve the body of oxygen.
Ligand exchange/substitution - Answer when one ligand in a complex ion is replaced by
a different ligand
What are the four main geometries for complex ions? - Answer Octahedral, Tetrahedral,
Square planar, Linear
What ligands tend to form octahedral complexes? - Answer water and ammonia
What ligands tend to form tetrahedral complexes? - Answer Chloride
What ligands tend to form square planar complexes? - Answer Nickel, Palladium,
Platinum
What ligands tend to form linear complexes? - Answer Copper, silver and gold
What type of isomerism can square planar complexes exhibit? - Answer cis-trans
isomerism
What does cisplatin look like? - Answer
What does transplatin look like? - Answer
Formula for Tollens' reagent and what does it test for? - Answer (Tests for aldehydes
and forms a silver mirror)
what type of isomerism is cis-trans isomerism - Answer Stereoisomerism
What type of isomerism can octahedral molecules with three bidentate ligands show? -
Answer Optical isomerism
factors affecting shape of ligand - Answer -central metal ion present
-ligands
In the presence of ligands, what happens to electrons? - Answer The orbitals will split.
Some of them gain energy, and some of them lose energy.
What is delta E in transition metals? - Answer The difference in energy of the excited
state and the ground state of the electron
what colour is {Fe(H2O)6}2+ - Answer pale green
Transition Metal definition - Answer D block elements that form at least one stable ion
with a partially filled d orbital
Classic elements which are not transition metals despite being D-Block elements -
Answer Scandium and Zinc
properties of transition metals which are NOT shared by other metals - Answer -multiple
oxidation states
-coloured ions in solution
-great catalysts
-form complexes with ligands
ligand - Answer a molecule which forms a dative bond with a transition metal
complex ion - Answer A transition metal ion bonded to one or more ligands by
coordinate bonds
co-ordination number - Answer The number of co-ordinate bonds formed to a central
metal ion
What is an example of incomplete ligand substitution? - Answer [Cu(NH3)6]2+ to
[Cu(NH3)4(H2O)2]2+
why does the coordination number not change when substituting water for ammonia ? -
Answer because they are of a similar size
Why does incomplete ligand substitution usually occur? - Answer when substituting
ligands of a different size
Denticity - Answer the number of dative bonds that can be formed with a transition
metal by one ligand
bidentate - Answer When a ligand can form two co-ordinate bonds in a complex ion.
monodentate (or unidentate) - Answer A ligand that can form one bond
Multidentate - Answer A ligand that can form multiple bonds
Chelate effect - Answer the ability of multidentate ligands to form more stable metal
complexes than those formed by similar monodentate ligands
Why is the chelate effect a largely entropic effect? - Answer As you the number of
moles of molecules in the products of the reaction increase. This leads to a large
increase in entropy and this brings the Gibbs free energy below zero for the change.
, AQA A Level Chemistry 2022 - Paper 3
Why is enthalpy change negligible in ligand substitution? - Answer The (dative) bonds
being broken and made are the same strength, amount and type.
Why is carbon monoxide toxic? - Answer CO can from a strong dative bond with
haemoglobin. This is a stronger bond than that made with oxygen and so it replaces the
oxygen attaching to the haemoglobin. This can starve the body of oxygen.
Ligand exchange/substitution - Answer when one ligand in a complex ion is replaced by
a different ligand
What are the four main geometries for complex ions? - Answer Octahedral, Tetrahedral,
Square planar, Linear
What ligands tend to form octahedral complexes? - Answer water and ammonia
What ligands tend to form tetrahedral complexes? - Answer Chloride
What ligands tend to form square planar complexes? - Answer Nickel, Palladium,
Platinum
What ligands tend to form linear complexes? - Answer Copper, silver and gold
What type of isomerism can square planar complexes exhibit? - Answer cis-trans
isomerism
What does cisplatin look like? - Answer
What does transplatin look like? - Answer
Formula for Tollens' reagent and what does it test for? - Answer (Tests for aldehydes
and forms a silver mirror)
what type of isomerism is cis-trans isomerism - Answer Stereoisomerism
What type of isomerism can octahedral molecules with three bidentate ligands show? -
Answer Optical isomerism
factors affecting shape of ligand - Answer -central metal ion present
-ligands
In the presence of ligands, what happens to electrons? - Answer The orbitals will split.
Some of them gain energy, and some of them lose energy.
What is delta E in transition metals? - Answer The difference in energy of the excited
state and the ground state of the electron
