AQA GCSE CHEMISTRY: ORGANIC CHEMISTRY
QUESTIONS WITH CORRECT ANSWERS 2026
Why is crude oil a finite resource? - CORRECT ANSWER -- it will eventually run out
What is crude oil the remains of? - CORRECT ANSWER --
crude oil is the remains of an ancient biomass consisting mainly of plankton that was buried in mud
What is crude oil a mixture of? - CORRECT ANSWER --
crude oil is a mixture of a very large number of compounds
- most of the compounds in crude oil are hydrocarbons
What are hydrocarbons? - CORRECT ANSWER --
molecules that are made up of hydrogen and carbon atoms only
What are most of the hydrocarbons in crude oil? - CORRECT ANSWER -alkanes
What is the general formula for the homologous series of alkanes? - CORRECT ANSWER -CₙH₂ₙ₊₂
How are single covalent bonds shown in chemical formulas? - CORRECT ANSWER -
a single line joining two atoms
What is the structure and formula of methane? - CORRECT ANSWER -CH₄
What is the structure and formula of ethane? - CORRECT ANSWER -C₂H₆
What is the structure and formula of propane? - CORRECT ANSWER -C₃H₈
What is the structure and formula of butane? - CORRECT ANSWER -C₄H₁₀
, What does it mean if alkanes are saturated molecules? - CORRECT ANSWER --
the carbon atoms are fully bonded to hydrogen atoms
- all of the bonds are single
What does viscosity mean? - CORRECT ANSWER -thickness of a fluid (e.g. honey is very viscous)
- fluids with a high viscosity flow slowly
How does the size of the hydrocarbon molecules affect their viscosity? - CORRECT ANSWER --
as the size of the hydrocarbon molecules inceases, the molecules get more viscous
What does flammability mean? - CORRECT ANSWER -how easily a hydrocarbon combusts (burns)
How does the size of the hydrocarbon molecules affect their flammability? - CORRECT ANSWER --
short chain hydrocarbons are extremely flammable
- increasing the size of the hydrocarbon molecule decreases its flammability (they get harder to burn)
How does the size of the hydrocarbon molecules affect their boiling point? - CORRECT ANSWER --
short chain hydrocarbons have low boiling points
-
as the size of the hydrocarbon molecule increases, their boilng points get higher (they require a highe
r temperature to break the intermolecular forces)
What does boiling point mean? - CORRECT ANSWER -the temperature at which a liquid turns to a gas
Why are hydrocarbons used as fuels? - CORRECT ANSWER -- they release energy when combusted
What happens during the combustion of hydrocarbons? - CORRECT ANSWER --
during combustion, the carbon and hydrogen atoms react with oxygen (the carbon and hydrogen are
oxidised)
What does complete combustion mean?
QUESTIONS WITH CORRECT ANSWERS 2026
Why is crude oil a finite resource? - CORRECT ANSWER -- it will eventually run out
What is crude oil the remains of? - CORRECT ANSWER --
crude oil is the remains of an ancient biomass consisting mainly of plankton that was buried in mud
What is crude oil a mixture of? - CORRECT ANSWER --
crude oil is a mixture of a very large number of compounds
- most of the compounds in crude oil are hydrocarbons
What are hydrocarbons? - CORRECT ANSWER --
molecules that are made up of hydrogen and carbon atoms only
What are most of the hydrocarbons in crude oil? - CORRECT ANSWER -alkanes
What is the general formula for the homologous series of alkanes? - CORRECT ANSWER -CₙH₂ₙ₊₂
How are single covalent bonds shown in chemical formulas? - CORRECT ANSWER -
a single line joining two atoms
What is the structure and formula of methane? - CORRECT ANSWER -CH₄
What is the structure and formula of ethane? - CORRECT ANSWER -C₂H₆
What is the structure and formula of propane? - CORRECT ANSWER -C₃H₈
What is the structure and formula of butane? - CORRECT ANSWER -C₄H₁₀
, What does it mean if alkanes are saturated molecules? - CORRECT ANSWER --
the carbon atoms are fully bonded to hydrogen atoms
- all of the bonds are single
What does viscosity mean? - CORRECT ANSWER -thickness of a fluid (e.g. honey is very viscous)
- fluids with a high viscosity flow slowly
How does the size of the hydrocarbon molecules affect their viscosity? - CORRECT ANSWER --
as the size of the hydrocarbon molecules inceases, the molecules get more viscous
What does flammability mean? - CORRECT ANSWER -how easily a hydrocarbon combusts (burns)
How does the size of the hydrocarbon molecules affect their flammability? - CORRECT ANSWER --
short chain hydrocarbons are extremely flammable
- increasing the size of the hydrocarbon molecule decreases its flammability (they get harder to burn)
How does the size of the hydrocarbon molecules affect their boiling point? - CORRECT ANSWER --
short chain hydrocarbons have low boiling points
-
as the size of the hydrocarbon molecule increases, their boilng points get higher (they require a highe
r temperature to break the intermolecular forces)
What does boiling point mean? - CORRECT ANSWER -the temperature at which a liquid turns to a gas
Why are hydrocarbons used as fuels? - CORRECT ANSWER -- they release energy when combusted
What happens during the combustion of hydrocarbons? - CORRECT ANSWER --
during combustion, the carbon and hydrogen atoms react with oxygen (the carbon and hydrogen are
oxidised)
What does complete combustion mean?
