A LEVEL CHEMISTRY B (SALTERS):
FUNDAMENTALS OF CHEMISTRY PRACTICE
EXAMINATION 2026 QUESTIONS WITH
ANSWERS GRADED A+
◍ State Hess's Law.
Answer: The total enthalpy change of a reaction is independent of the route
taken.
◍ What is meant by standard conditions?.
Answer: .Temp - 25 dc, 298K.Pressure - 100kPa.Conc - 1 mol /
dm-3.Standard state
◍ What is meant by standard enthalpy change of neutralisation?.
Answer: The enthalpy change when one mole of water is formed in a
neutralisation reaction under standard conditions (-57kj/mol for any strong
acid + alkali)
◍ Shape of a molecule with 4 bonding pairs of electrons and explain?.
Answer: Tetrahedral, 109.5Electrons arranged to minimise repulsion
◍ Shape of a molecule with 2 bonding electron pairs?.
Answer: Linear , 180Electrons arranged to minimise repulsion
◍ Shape of molecule with 3 bonding electron pairs?.
Answer: Trigonal Planar, 120
◍ Ideal gas equation?.
Answer: pv = nRt(penis vagina = naughty rectum tickle)
◍ What is a sub-shell?.
Answer: A group of orbitals of the same type within a shell e.g the 2p
, subshell contains 3 p orbitals in the second shell
◍ What is an atomic orbital?.
Answer: A region around the nucleus that can hold up to 2 electrons with
opposite spins
◍ What is the empirical formula?.
Answer: The simplest whole number ratio of atoms of each element in a
compound
◍ What is an aromatic compound?.
Answer: A compound that contains at least one benzene ring
◍ What is an aliphatic compound?.
Answer: An organic compound that does not contain a benzene ring
◍ What is an arene?.
Answer: An aromatic hydrocarbon.
◍ What is a structural isomer?.
Answer: Compounds with the same molecular formula but different
structural formula (may have alkyl group)
◍ What is a benzene ring?.
Answer: Simplest aromatic hydrocarbon C6H6
◍ General formula for cycloalkanes?.
Answer: CnH2n
◍ Why don't alkanes mix with water?.
Answer: Alkanes contain non-polar molecules but water contains polar
molecules that attract each other and stop the alkane from mixing
◍ What is a heterogeneous catalyst?.
Answer: A catalyst in a different physical state to the reactants
◍ How do heterogeneous catalysts work?.
Answer: 1)Reactant molecules bond with catalyst surface =
adsorption2)Reactant bonds are broken, forming radicals (atoms with
, unpaired electrons)3)Radicals get together to make new molecules4)New
molecules detach from catalyst - desorption and diffuses away
◍ Why may a catalyst become poisoned?.
Answer: The poison molecule (eg CO) bonds to the catalyst more strongly
than the reactant so the catalyst is blocked to the reaction
◍ What letter is used to represent atomic number?.
Answer: Z
◍ What state of matter do enthalpy values apply to?.
Answer: Gaseous
◍ Why might a calculated bond enthalpy be different from the standard
value?.
Answer: 1)The value in data sheets is the average bond enthalpy from
several compounds 2)Reactants may not be in a gaseous state (e.g water and
alcohols)
◍ What are sterioisomers?.
Answer: Molecules with the same structural formula but a different spatial
arrangement of atoms
◍ What is the difference between E/Z isomers?.
Answer: E (trans) isomers have the H group on opposite sides but Z (cis)
isomers have the H group on zee zame zide
◍ Why can't alkanes be E/Z isomers?.
Answer: E/Z isomerism occurs because atoms cannot rotate about the C=C
double bond but atoms can rotate about single bonds like in alkanes
◍ How does a mass spectrometer work?.
Answer: 1) Atoms are ionised to become cations2) Cations are accelerated
down a chamber3) Ions are separated according to mass/charge ratio4) Mass
an abundance of each ion is detected
◍ What are absorption spectra?.
Answer: Black lines on a coloured background that represent certain
FUNDAMENTALS OF CHEMISTRY PRACTICE
EXAMINATION 2026 QUESTIONS WITH
ANSWERS GRADED A+
◍ State Hess's Law.
Answer: The total enthalpy change of a reaction is independent of the route
taken.
◍ What is meant by standard conditions?.
Answer: .Temp - 25 dc, 298K.Pressure - 100kPa.Conc - 1 mol /
dm-3.Standard state
◍ What is meant by standard enthalpy change of neutralisation?.
Answer: The enthalpy change when one mole of water is formed in a
neutralisation reaction under standard conditions (-57kj/mol for any strong
acid + alkali)
◍ Shape of a molecule with 4 bonding pairs of electrons and explain?.
Answer: Tetrahedral, 109.5Electrons arranged to minimise repulsion
◍ Shape of a molecule with 2 bonding electron pairs?.
Answer: Linear , 180Electrons arranged to minimise repulsion
◍ Shape of molecule with 3 bonding electron pairs?.
Answer: Trigonal Planar, 120
◍ Ideal gas equation?.
Answer: pv = nRt(penis vagina = naughty rectum tickle)
◍ What is a sub-shell?.
Answer: A group of orbitals of the same type within a shell e.g the 2p
, subshell contains 3 p orbitals in the second shell
◍ What is an atomic orbital?.
Answer: A region around the nucleus that can hold up to 2 electrons with
opposite spins
◍ What is the empirical formula?.
Answer: The simplest whole number ratio of atoms of each element in a
compound
◍ What is an aromatic compound?.
Answer: A compound that contains at least one benzene ring
◍ What is an aliphatic compound?.
Answer: An organic compound that does not contain a benzene ring
◍ What is an arene?.
Answer: An aromatic hydrocarbon.
◍ What is a structural isomer?.
Answer: Compounds with the same molecular formula but different
structural formula (may have alkyl group)
◍ What is a benzene ring?.
Answer: Simplest aromatic hydrocarbon C6H6
◍ General formula for cycloalkanes?.
Answer: CnH2n
◍ Why don't alkanes mix with water?.
Answer: Alkanes contain non-polar molecules but water contains polar
molecules that attract each other and stop the alkane from mixing
◍ What is a heterogeneous catalyst?.
Answer: A catalyst in a different physical state to the reactants
◍ How do heterogeneous catalysts work?.
Answer: 1)Reactant molecules bond with catalyst surface =
adsorption2)Reactant bonds are broken, forming radicals (atoms with
, unpaired electrons)3)Radicals get together to make new molecules4)New
molecules detach from catalyst - desorption and diffuses away
◍ Why may a catalyst become poisoned?.
Answer: The poison molecule (eg CO) bonds to the catalyst more strongly
than the reactant so the catalyst is blocked to the reaction
◍ What letter is used to represent atomic number?.
Answer: Z
◍ What state of matter do enthalpy values apply to?.
Answer: Gaseous
◍ Why might a calculated bond enthalpy be different from the standard
value?.
Answer: 1)The value in data sheets is the average bond enthalpy from
several compounds 2)Reactants may not be in a gaseous state (e.g water and
alcohols)
◍ What are sterioisomers?.
Answer: Molecules with the same structural formula but a different spatial
arrangement of atoms
◍ What is the difference between E/Z isomers?.
Answer: E (trans) isomers have the H group on opposite sides but Z (cis)
isomers have the H group on zee zame zide
◍ Why can't alkanes be E/Z isomers?.
Answer: E/Z isomerism occurs because atoms cannot rotate about the C=C
double bond but atoms can rotate about single bonds like in alkanes
◍ How does a mass spectrometer work?.
Answer: 1) Atoms are ionised to become cations2) Cations are accelerated
down a chamber3) Ions are separated according to mass/charge ratio4) Mass
an abundance of each ion is detected
◍ What are absorption spectra?.
Answer: Black lines on a coloured background that represent certain
