AQA A LEVEL CHEMISTRY Exam
Questions with Accurate Answers
Guaranteed Pass Latest Version
1. what is a ligand - ANSWER An atom, ion or molecule which can donate a
lone electron pair
2. what is a coordinate bond - ANSWER Co-ordinate bonding is when the
shared pair of electrons in the covalent bond come from only one of the
bonding atoms
3. what is coordination number - ANSWER The number of co-ordinate bonds
formed to a central metal ion
4. why is carbon monoxide toxic - ANSWER CO is toxic to humans as CO can
from a strong coordinate bond with haemoglobin. This is a stronger bond
than that made with oxygen and so it replaces the oxygen attaching to the
haemoglobin
5. what is the chelate effect - ANSWER The substitution of monodentate
ligand with a bidentate or a multidentate ligand leads to a more stable
complex. This chelate effect can be explained in terms of a positive entropy
change in these reactions as more molecules of products than reactants
6. type of isomerism shown in square planar/octahedral complexes - ANSWER
E-Z
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, 7. isomerism shown only in octahedral complexes - ANSWER Complexes with
3 bidentate ligands can form two optical isomers (non-superimposable
mirror images)
8. Relative atomic mass - ANSWER The average mass of an atom of an
element, relative to 1/12th of the mass of an atom of Carbon-12
9. Relative molecular mass - ANSWER Average mass of a molecule compared
to 1/12th of the mass of a carbon-12 atom
10. The Avogradro constant - ANSWER the number of particles in a mole
11. ideal gas equation - ANSWER pV = nRT
12. empirical formula - ANSWER the simplest whole number ratio of atoms of
each element in a compound
13. percentage atom economy - ANSWER (Mass of desired product/total mass
of reactants) x 100
14. ionic bonding - ANSWER the electrostatic attraction between oppositely
charged ions in a lattice
15. covalent bond - ANSWER a shared pair of electrons between non-metal
elements
16. co-ordinate bond - ANSWER a shared pair of electrons where both electrons
are supplied by one atom
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, 17. repulsion in shapes of molecules - ANSWER Lone pair-lone pair > lone
pair-bonding pair > bonding pair-bonding pair
18. electronegativity - ANSWER the power of an atom to attract the pair of
electrons in a covalent bond
19. Benzene - ANSWER An unsaturated carbon ring, with delocalised electrons
in the centre, which cannot undergo addition reactions
20. 152 - ANSWER Benzene is more stable than cyclohexene by a certain
enthalpy change
21. Electrophilic Substitution - ANSWER The mechanism to add a different R
group to a benzene ring. This is the main type of reaction that occurs as the
benzene ring is an area of high electron density so requires like charge
displacement. The ring is also very stable so the reaction has to be of a high
energy to destabilise the ring
22. Nitration - ANSWER The substitution of NO2 for one of the H on a benzene
rings
23. TNT - ANSWER Main use of a specific nitrated arene
24. Friedel-Crafts Acylation - ANSWER The substitution mechanism catalysed
by AlCl3. Which reforms at the end of the reaction
25. What are carbonyls - ANSWER compounds with a C=O bond
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, 26. When is it an aldehyde? - ANSWER when C=O is on the end of the chain
with an H attached
27. When is it a ketone? - ANSWER if the C=O is in the middle of the chain
28. What intermolecular forces are in carbonyls? - ANSWER cant hydrogen
bond but have permanent dipole forces
29. Why are smaller carbonyls soluble in water? - ANSWER because they can
form hydrogen bonds with water
30. Why is the C=O bond polarised? - ANSWER because O is more
leectronegative than carbon,
31. what does postiive carbon atom do? - ANSWER attracts nucelophiles
32. Contrast between C=O and C=C in alkenes? - ANSWER C=O is stronger
and does not undergo addition reactions easily
33. Primary alcohols are oxidise into what? - ANSWER aldehydes
34. Aldehyes are oxidise into what (or primary alcohols further oxidises into
what) - ANSWER carboxylic acid
35. Secondary alcohols are oxidised into what? - ANSWER ketones
@#$%^$#@$%^&*(&^%$#@$
Questions with Accurate Answers
Guaranteed Pass Latest Version
1. what is a ligand - ANSWER An atom, ion or molecule which can donate a
lone electron pair
2. what is a coordinate bond - ANSWER Co-ordinate bonding is when the
shared pair of electrons in the covalent bond come from only one of the
bonding atoms
3. what is coordination number - ANSWER The number of co-ordinate bonds
formed to a central metal ion
4. why is carbon monoxide toxic - ANSWER CO is toxic to humans as CO can
from a strong coordinate bond with haemoglobin. This is a stronger bond
than that made with oxygen and so it replaces the oxygen attaching to the
haemoglobin
5. what is the chelate effect - ANSWER The substitution of monodentate
ligand with a bidentate or a multidentate ligand leads to a more stable
complex. This chelate effect can be explained in terms of a positive entropy
change in these reactions as more molecules of products than reactants
6. type of isomerism shown in square planar/octahedral complexes - ANSWER
E-Z
@#$%^$#@$%^&*(&^%$#@$
, 7. isomerism shown only in octahedral complexes - ANSWER Complexes with
3 bidentate ligands can form two optical isomers (non-superimposable
mirror images)
8. Relative atomic mass - ANSWER The average mass of an atom of an
element, relative to 1/12th of the mass of an atom of Carbon-12
9. Relative molecular mass - ANSWER Average mass of a molecule compared
to 1/12th of the mass of a carbon-12 atom
10. The Avogradro constant - ANSWER the number of particles in a mole
11. ideal gas equation - ANSWER pV = nRT
12. empirical formula - ANSWER the simplest whole number ratio of atoms of
each element in a compound
13. percentage atom economy - ANSWER (Mass of desired product/total mass
of reactants) x 100
14. ionic bonding - ANSWER the electrostatic attraction between oppositely
charged ions in a lattice
15. covalent bond - ANSWER a shared pair of electrons between non-metal
elements
16. co-ordinate bond - ANSWER a shared pair of electrons where both electrons
are supplied by one atom
@#$%^$#@$%^&*(&^%$#@$
, 17. repulsion in shapes of molecules - ANSWER Lone pair-lone pair > lone
pair-bonding pair > bonding pair-bonding pair
18. electronegativity - ANSWER the power of an atom to attract the pair of
electrons in a covalent bond
19. Benzene - ANSWER An unsaturated carbon ring, with delocalised electrons
in the centre, which cannot undergo addition reactions
20. 152 - ANSWER Benzene is more stable than cyclohexene by a certain
enthalpy change
21. Electrophilic Substitution - ANSWER The mechanism to add a different R
group to a benzene ring. This is the main type of reaction that occurs as the
benzene ring is an area of high electron density so requires like charge
displacement. The ring is also very stable so the reaction has to be of a high
energy to destabilise the ring
22. Nitration - ANSWER The substitution of NO2 for one of the H on a benzene
rings
23. TNT - ANSWER Main use of a specific nitrated arene
24. Friedel-Crafts Acylation - ANSWER The substitution mechanism catalysed
by AlCl3. Which reforms at the end of the reaction
25. What are carbonyls - ANSWER compounds with a C=O bond
@#$%^$#@$%^&*(&^%$#@$
, 26. When is it an aldehyde? - ANSWER when C=O is on the end of the chain
with an H attached
27. When is it a ketone? - ANSWER if the C=O is in the middle of the chain
28. What intermolecular forces are in carbonyls? - ANSWER cant hydrogen
bond but have permanent dipole forces
29. Why are smaller carbonyls soluble in water? - ANSWER because they can
form hydrogen bonds with water
30. Why is the C=O bond polarised? - ANSWER because O is more
leectronegative than carbon,
31. what does postiive carbon atom do? - ANSWER attracts nucelophiles
32. Contrast between C=O and C=C in alkenes? - ANSWER C=O is stronger
and does not undergo addition reactions easily
33. Primary alcohols are oxidise into what? - ANSWER aldehydes
34. Aldehyes are oxidise into what (or primary alcohols further oxidises into
what) - ANSWER carboxylic acid
35. Secondary alcohols are oxidised into what? - ANSWER ketones
@#$%^$#@$%^&*(&^%$#@$
