AQA A LEVEL CHEMISTRY PAPER 1 REAL EXAM QUESTIONS
WITH 100% RATED CORRECT ANSWERS (ACCURATELY PASSED)
2025 LATEST UPDATED GET A+
Explain what is meant by the term co-ordinate bond - (ANSWER)a covalent bond in which
both electrons are donated by one atom
Define the term Ligand - (ANSWER)Atom, ion or molecule which can donate a pair of
electrons to a metal ion
What can lattice enthalpy defined as? (2 things) - (ANSWER)Lattice enthalpy of formation and
lattice enthalpy of dissociation
Why is the experimental value for lattice dissociation of some compounds greater than the
theoretical value? - (ANSWER)the bonding is not 100% ionic/ there is some covalent character/
there is additional covalent bonding
what does the perfect ionic model assume? - (ANSWER)The bonding in the compound is not
100% ionic. In the model the ions are perfect spheres/point charges are not distorted
What 2 things might cause a different lattice enthalpy? - (ANSWER)Enthalpy of bond
dissociation (eg halogens)
Enthalpy of formation
why is the lattice enthalpy greater for ions with a high charge? - (ANSWER)There is a stronger
attraction
Why is the lattice enthalpy greater for smaller ions? - (ANSWER)smaller ions are more closely
packed in the lattice
there is a stronger attraction
, what is the relationship between enthalpy of lattice dissociation and enthalpy of lattice
formation? - (ANSWER)same numerical value but different signs
State Hess' law - (ANSWER)Enthalpy change for any chemical reaction is independent of the
route taken, and depends only on the initial and final states.
Why is the second electron affinity endothermic? - (ANSWER)Repulsion of the negative ion
with the negative electron being added
Define enthalpy of hydration - (ANSWER)The enthalpy change when 1 mole of gaseous ions is
converted to one mole of aqueous ions
What does enthalpy of solution equal? - (ANSWER)enthalpy of solution = lattice dissociation +
enthalpy of hydration
(^H(solution)=^H(lattice dissociation)+^H(hydration))
what happens when and ionic compound dissolves in water? - (ANSWER)the ionic lattice
breaks up (enthalpy of lattice dissociation )
the polar water molecules form bonds with the ions (enthalpy of hydration)
define enthalpy of solution - (ANSWER)the enthalpy change when one mole of ionic
compounds dissolves in water to form a solution of infinite dilution
why do some compounds have covalent character? - (ANSWER)one of the ions is small and
has a large charge
this distorts the other ion
the ions are not spherical
WITH 100% RATED CORRECT ANSWERS (ACCURATELY PASSED)
2025 LATEST UPDATED GET A+
Explain what is meant by the term co-ordinate bond - (ANSWER)a covalent bond in which
both electrons are donated by one atom
Define the term Ligand - (ANSWER)Atom, ion or molecule which can donate a pair of
electrons to a metal ion
What can lattice enthalpy defined as? (2 things) - (ANSWER)Lattice enthalpy of formation and
lattice enthalpy of dissociation
Why is the experimental value for lattice dissociation of some compounds greater than the
theoretical value? - (ANSWER)the bonding is not 100% ionic/ there is some covalent character/
there is additional covalent bonding
what does the perfect ionic model assume? - (ANSWER)The bonding in the compound is not
100% ionic. In the model the ions are perfect spheres/point charges are not distorted
What 2 things might cause a different lattice enthalpy? - (ANSWER)Enthalpy of bond
dissociation (eg halogens)
Enthalpy of formation
why is the lattice enthalpy greater for ions with a high charge? - (ANSWER)There is a stronger
attraction
Why is the lattice enthalpy greater for smaller ions? - (ANSWER)smaller ions are more closely
packed in the lattice
there is a stronger attraction
, what is the relationship between enthalpy of lattice dissociation and enthalpy of lattice
formation? - (ANSWER)same numerical value but different signs
State Hess' law - (ANSWER)Enthalpy change for any chemical reaction is independent of the
route taken, and depends only on the initial and final states.
Why is the second electron affinity endothermic? - (ANSWER)Repulsion of the negative ion
with the negative electron being added
Define enthalpy of hydration - (ANSWER)The enthalpy change when 1 mole of gaseous ions is
converted to one mole of aqueous ions
What does enthalpy of solution equal? - (ANSWER)enthalpy of solution = lattice dissociation +
enthalpy of hydration
(^H(solution)=^H(lattice dissociation)+^H(hydration))
what happens when and ionic compound dissolves in water? - (ANSWER)the ionic lattice
breaks up (enthalpy of lattice dissociation )
the polar water molecules form bonds with the ions (enthalpy of hydration)
define enthalpy of solution - (ANSWER)the enthalpy change when one mole of ionic
compounds dissolves in water to form a solution of infinite dilution
why do some compounds have covalent character? - (ANSWER)one of the ions is small and
has a large charge
this distorts the other ion
the ions are not spherical
