AQA - chemistry - paper 2 -organic
chemistry – 2022-2023 | 159
Questions with solved Answers| A
Grade.
what is crude oil ? - --finite resource found in rocks and remaining of ancient biomass
made of plankton buried in mud .
-mixture of a large number of compounds which are mostly hydrocarbons
-What is a hydrocarbon? - -a compound made of hydrogen and carbon atoms only
-general formula for an alkane - -CnH2n+2
-how can hydrocarbons be separated in crude oil - -fractional distillation
-what uses do we have for the fractions of crude oil - -fuels and the petrochemical
industry
-what materials are produced by petrochemical industry - -solvents lubricants ,
polymers ,detergents
-why are there lots of natural and synthetic carbon compounds - -due to the ability of
carbon atoms to form families of similar compounds
-what happens to the flamability of a hydrocarbon as it becomes larger - -decreases
-what happens to the viscosity of a hydrocarbon as it becomes larger - -increases
-what happens to the melting/boiling point of hydrocarbons as it becomes larger - -
increases
,-what happens during combustion of hydrocarbon fuels - -carbon and hydrogen in the
fuel are fully oxidised to make carbon dioxide and water releasing energy
-what is the word equation for combustion of fuel from crude oil - -hydrocarbon +
oxygen --> carbon dioxide + water
-how can hydrocarbons be broken down into smaller molecules - -cracking
-what happens during catalytic cracking - -crude oil is vaporised and passed over a hot
cataylst
-what happens during steam cracking - -crude oil is vaporised and mixed with steam
and heated to high temperature
-what are the products of cracking - -smaller and useful alkanes and alkenes
-how can we test for alkenes - -add bromine water and if the colour changes to clear an
alkene is present
-what colour change happens when alkenes react with bromine - -orange bromine
water turns colourless
-what is meant by a functional group - -part of the molecule that determines how it
reacts
-how do alkenes react with hydrogen - --hydrogenation
-requires high temperatures and catalyst
-alkene converts to alkane
-formula for alkenes - -CnH2n
, -why are alkenes unsaturated - -They have a double carbon-carbon bond
-what is meant by Homologous series - -compounds that have the same funcitional
group
-what happens when you combust an alkene - -incomplete combustion takes place and
a smoky flame is released
-describe the reaction with alkenes with water - --hydration as the water must be steam
-produces an alcohol
-reversible reaction
-needs around 70 atmospheres of pressure and high temperature around 300 degrees
-describe the reaction with alkenes with halogens - -creates dio-halogen-alkene
-how is ethanol produced - --fermentation
-mix a sugar solution with yeast
-temperature around 30 degrees
-reaction must take place in anaerobic conditions
-What type of acids are carboxylic acids? - -weak acids
-what is the difference between polymers and monomers - -monomer has a double
carbon carbon bonds but polyemers have single carbon bonds
-explain how crude oil is separated by fractional distillation - --crude oil is heated and
hydrocarbons vaporise
-vapours rise up the column and cool
-hydrocarbons condense to become liquid at their boiling points
-compare cracking and distillation - -cracking involves a catalyst while distillation does
not
chemistry – 2022-2023 | 159
Questions with solved Answers| A
Grade.
what is crude oil ? - --finite resource found in rocks and remaining of ancient biomass
made of plankton buried in mud .
-mixture of a large number of compounds which are mostly hydrocarbons
-What is a hydrocarbon? - -a compound made of hydrogen and carbon atoms only
-general formula for an alkane - -CnH2n+2
-how can hydrocarbons be separated in crude oil - -fractional distillation
-what uses do we have for the fractions of crude oil - -fuels and the petrochemical
industry
-what materials are produced by petrochemical industry - -solvents lubricants ,
polymers ,detergents
-why are there lots of natural and synthetic carbon compounds - -due to the ability of
carbon atoms to form families of similar compounds
-what happens to the flamability of a hydrocarbon as it becomes larger - -decreases
-what happens to the viscosity of a hydrocarbon as it becomes larger - -increases
-what happens to the melting/boiling point of hydrocarbons as it becomes larger - -
increases
,-what happens during combustion of hydrocarbon fuels - -carbon and hydrogen in the
fuel are fully oxidised to make carbon dioxide and water releasing energy
-what is the word equation for combustion of fuel from crude oil - -hydrocarbon +
oxygen --> carbon dioxide + water
-how can hydrocarbons be broken down into smaller molecules - -cracking
-what happens during catalytic cracking - -crude oil is vaporised and passed over a hot
cataylst
-what happens during steam cracking - -crude oil is vaporised and mixed with steam
and heated to high temperature
-what are the products of cracking - -smaller and useful alkanes and alkenes
-how can we test for alkenes - -add bromine water and if the colour changes to clear an
alkene is present
-what colour change happens when alkenes react with bromine - -orange bromine
water turns colourless
-what is meant by a functional group - -part of the molecule that determines how it
reacts
-how do alkenes react with hydrogen - --hydrogenation
-requires high temperatures and catalyst
-alkene converts to alkane
-formula for alkenes - -CnH2n
, -why are alkenes unsaturated - -They have a double carbon-carbon bond
-what is meant by Homologous series - -compounds that have the same funcitional
group
-what happens when you combust an alkene - -incomplete combustion takes place and
a smoky flame is released
-describe the reaction with alkenes with water - --hydration as the water must be steam
-produces an alcohol
-reversible reaction
-needs around 70 atmospheres of pressure and high temperature around 300 degrees
-describe the reaction with alkenes with halogens - -creates dio-halogen-alkene
-how is ethanol produced - --fermentation
-mix a sugar solution with yeast
-temperature around 30 degrees
-reaction must take place in anaerobic conditions
-What type of acids are carboxylic acids? - -weak acids
-what is the difference between polymers and monomers - -monomer has a double
carbon carbon bonds but polyemers have single carbon bonds
-explain how crude oil is separated by fractional distillation - --crude oil is heated and
hydrocarbons vaporise
-vapours rise up the column and cool
-hydrocarbons condense to become liquid at their boiling points
-compare cracking and distillation - -cracking involves a catalyst while distillation does
not
