2025 AQA GCSE COMBINED SCIENCE: TRILOGY 8464/B/1F BIOLOGY PAPER 1F QUESTION
PAPER + MARK SCHEME
in terms of saturation, alkanes are saturated
in terms of saturation, alkenes are unsaturated
hydrocarbon a molecule containing only hydrogen and carbon atoms
carbohydrate a molecule containing only carbon, hydrogen and oxygen atoms
the process of oxidising carbohydrates in our cells respiration
the process of oxidising either hydrocarbons or carbohydrates quickly combustion
formula for aerobic respiration C₆H₁₂O₆ + 6O₂ ➜ 6CO₂ + 6H₂O
when writing complete combustion formulae for even-numbered alkanes or odd-numbered
alkenes, you need to double the alkane/alkene
crude oil is a fossil fuel
equipment used to fractionally distill crude oil fractionating column
how a fractionating column works crude oil is heated to a high temperature so that
everything except the residue evaporates, then it is gradually cooled and as the different
fractions condense at different temperatures they are collected
,each fraction of crude oil contains similar alkanes
fractional distillation is the process by which fractions of crude oil are separated
general formula for the combustion of hydrocarbons hydrocarbon + oxygen ➜ carbon
dioxide + water
incomplete combustion takes place due to a shortage of air
products of incomplete combustion carbon dioxide, water, carbon monoxide and/or carbon
(soot)
carbon monoxide is a poisonous gas because it reduces the blood's ability to carry oxygen
fractions of crude oil: LPG (liquid petroleum gas) highly flammable, very volatile, BP < 0,
colourless, contains propane/butane, used for heating/cooking on the move
fractions of crude oil: gasoline highly flammable, low viscosity, colourless, a.k.a. petrol,
used as car fuel
fractions of crude oil: naphtha highly flammable, low viscosity, colourless, makes plastics,
used as cleaning fluid/solvent, found in petrol
fractions of crude oil: kerosene highly flammable, yellow, a.k.a. paraffin, used as aviation
fuel and in central heating
, fractions of crude oil: diesel medium viscosity, orange/brown, fuel for lorries, cars, buses and
some boats
fractions of crude oil: lubricating oil medium viscosity, orange/brow, translucent, used as a
lubricant for moving parts
fractions of crude oil: fuel oil high BP, not volatile, not flammable, very viscous, black, opaque,
for large engines, ships and industrial boilers
fractions of crude oil: residue/bitumen very viscous, black, opaque, contains paraffin waxes
and bitumen
paraffin waxes are used for candles and waterproofing
bitumen is used for roads and waterproofing
fractions with a low boiling point evaporate easily
volatility the ability to evaporate easily
the more volatile a fraction is the easier it mixes with air
volatile fractions ignite and burn more easily
flammable ignite and burn easily
the exact composition of crude oil varies depending on where in the world it comes from
PAPER + MARK SCHEME
in terms of saturation, alkanes are saturated
in terms of saturation, alkenes are unsaturated
hydrocarbon a molecule containing only hydrogen and carbon atoms
carbohydrate a molecule containing only carbon, hydrogen and oxygen atoms
the process of oxidising carbohydrates in our cells respiration
the process of oxidising either hydrocarbons or carbohydrates quickly combustion
formula for aerobic respiration C₆H₁₂O₆ + 6O₂ ➜ 6CO₂ + 6H₂O
when writing complete combustion formulae for even-numbered alkanes or odd-numbered
alkenes, you need to double the alkane/alkene
crude oil is a fossil fuel
equipment used to fractionally distill crude oil fractionating column
how a fractionating column works crude oil is heated to a high temperature so that
everything except the residue evaporates, then it is gradually cooled and as the different
fractions condense at different temperatures they are collected
,each fraction of crude oil contains similar alkanes
fractional distillation is the process by which fractions of crude oil are separated
general formula for the combustion of hydrocarbons hydrocarbon + oxygen ➜ carbon
dioxide + water
incomplete combustion takes place due to a shortage of air
products of incomplete combustion carbon dioxide, water, carbon monoxide and/or carbon
(soot)
carbon monoxide is a poisonous gas because it reduces the blood's ability to carry oxygen
fractions of crude oil: LPG (liquid petroleum gas) highly flammable, very volatile, BP < 0,
colourless, contains propane/butane, used for heating/cooking on the move
fractions of crude oil: gasoline highly flammable, low viscosity, colourless, a.k.a. petrol,
used as car fuel
fractions of crude oil: naphtha highly flammable, low viscosity, colourless, makes plastics,
used as cleaning fluid/solvent, found in petrol
fractions of crude oil: kerosene highly flammable, yellow, a.k.a. paraffin, used as aviation
fuel and in central heating
, fractions of crude oil: diesel medium viscosity, orange/brown, fuel for lorries, cars, buses and
some boats
fractions of crude oil: lubricating oil medium viscosity, orange/brow, translucent, used as a
lubricant for moving parts
fractions of crude oil: fuel oil high BP, not volatile, not flammable, very viscous, black, opaque,
for large engines, ships and industrial boilers
fractions of crude oil: residue/bitumen very viscous, black, opaque, contains paraffin waxes
and bitumen
paraffin waxes are used for candles and waterproofing
bitumen is used for roads and waterproofing
fractions with a low boiling point evaporate easily
volatility the ability to evaporate easily
the more volatile a fraction is the easier it mixes with air
volatile fractions ignite and burn more easily
flammable ignite and burn easily
the exact composition of crude oil varies depending on where in the world it comes from
