AQA AS CHEMISTRY 7404 2 ORGANIC AND
PHYSICAL CHEMISTRY EXAMPREP 2026
MARK SCHEME WITH FULL SOLUTION
⩥ write an equation to show the complete combustion of CH3SH. state
why cao can be used to remove the sulfur- containing product of this
combustion reaction. state one pollution that is caused by the release of
this sulfur containing product in to the atmosphere? Answer: CH3SH +
3O2 ~ CO2 + 2H20 + SO2
cao is basic and so2 is acidic
cao+so2~ caso3
acid rain
⩥ multiple choice question ? Answer: A / longest answer
⩥ which of these substances does not contribute to the greenhouse
effect? Answer: nitrogen
⩥ state what is mean by the term hydrocarbon and saturated ? Answer:
hydrocarbon is a molecule containing hydrogen and carbon atoms only
saturated meaning single bonds only
, ⩥ give the molecular formula of an alkane with 10 carbon atoms ?
Answer: C10H22
⩥ write an equation to illustrate the thermal cracking of 1 molecule of
tetradecane, C14H30, in which the products are ethene and propene, in
the ratio 2:7, and one other product? Answer: C14H30 ~ 2C2H4 + C3H6
+ C7H16
⩥ state one essential condition of the formation of NO in an engine.
write an equation for the reaction in which NO is formed ? Answer: high
temperature
NO+O2 ~ 2NO
⩥ name one of the metals used as a catalyst in a catalytic converter?
Answer: platinum
⩥ write an equation to show how CO and NO react with each other in a
catalytic converter ? Answer: 2CO + 2No ~ N2 + 2CO2
⩥ state why sulphur gas is sometimes found in the exhaust gases of
petrol engined gases. give ine adversed effect of SO2 on the
environment. reason for SO2 in exhaust gases ? Answer: fraction contain
sulphur containing impurities which burn to form SO2
acid rain
PHYSICAL CHEMISTRY EXAMPREP 2026
MARK SCHEME WITH FULL SOLUTION
⩥ write an equation to show the complete combustion of CH3SH. state
why cao can be used to remove the sulfur- containing product of this
combustion reaction. state one pollution that is caused by the release of
this sulfur containing product in to the atmosphere? Answer: CH3SH +
3O2 ~ CO2 + 2H20 + SO2
cao is basic and so2 is acidic
cao+so2~ caso3
acid rain
⩥ multiple choice question ? Answer: A / longest answer
⩥ which of these substances does not contribute to the greenhouse
effect? Answer: nitrogen
⩥ state what is mean by the term hydrocarbon and saturated ? Answer:
hydrocarbon is a molecule containing hydrogen and carbon atoms only
saturated meaning single bonds only
, ⩥ give the molecular formula of an alkane with 10 carbon atoms ?
Answer: C10H22
⩥ write an equation to illustrate the thermal cracking of 1 molecule of
tetradecane, C14H30, in which the products are ethene and propene, in
the ratio 2:7, and one other product? Answer: C14H30 ~ 2C2H4 + C3H6
+ C7H16
⩥ state one essential condition of the formation of NO in an engine.
write an equation for the reaction in which NO is formed ? Answer: high
temperature
NO+O2 ~ 2NO
⩥ name one of the metals used as a catalyst in a catalytic converter?
Answer: platinum
⩥ write an equation to show how CO and NO react with each other in a
catalytic converter ? Answer: 2CO + 2No ~ N2 + 2CO2
⩥ state why sulphur gas is sometimes found in the exhaust gases of
petrol engined gases. give ine adversed effect of SO2 on the
environment. reason for SO2 in exhaust gases ? Answer: fraction contain
sulphur containing impurities which burn to form SO2
acid rain
