C14 - Organic Chemistry Flashcards
Name three fossil fuels [3]
Coal / natural gas / petroleum (crude oil)
What is the main constituent of natural gas? [1]
Methane
Describe petroleum [1]
A mixture of hydrocarbons called fractions
Describe what is similar about the molecules within a fraction [2]
They will be of similar size / they will have similar boiling points
What is the process used to separate the fractions within petroleum and why can the fractions be separated in this way? [2]
Fractional distillation / separates hydrocarbon fractions based on their boiling point
Describe the process of fractional distillation [3]
Petroleum is vaporised / fractionating column is hot at the bottom and cooler at the top / as hydrocarbon vapours rise up the column they condense at different boiling points
Describe the fractions that vapourise at the top fo the column [4]
Smaller / lower boiling point / more volatile / less viscous
What is a use of refinery gas? [1]
Bottled gas for heating and cooking
What is a use of the gasoline fraction? [1]
Fuel (petrol) in cars
What is a use of the naptha fraction? [1]
Feedstock for making chemicals
What is a use of the diesel oil / gas oil fraction [1]
Fuel in diesel engines
What is a use of the bitumen fraction? [1]
Road surfaces
What is a homologous series? [2]
A family of compounds with the same general formula / similar chemical properties
Describe alkanes [2]
Saturated hydrocarbons / molecules contain only single covalent bonds
Describe the properties of alkanes [1]
Fairly unreactive (except in terms of burning)
Describe the complete combustion of hydrocarbons [1]
React with oxygen to produce carbon dioxide and water
Describe alkenes [2]
Unsaturated hydrocarbons / molecules contain at least one double covalent bond between carbon atoms
What is cracking? [3]
Using heat to break long chain alkanes / into shorter chain alkanes and alkenes / requires a catalyst such as aluminium oxide
Name the first four alkanes / first 3 alkenes [2]
Methane, ethane, propane, butane / ethene, propene, butene
How can alkenes be tested for and what is the positive result? [2]
Bromine water / bromine water turns from orange to colourless
What type of reactions do alkenes undergo? [1]
Addition reactions
What is the product in the reaction between an alkene and hydrogen? [1]
Alkane
What is the product in the reaction between an alkene and bromine? [1]
Di-bromo-alkane
What is the product in the reaction between an alkene and steam? [1]
Alcohol
Describe two ways that ethanol can be formed [2]
Fermentation and the reaction between ethene and steam
Describe two uses of ethanol [2]
Solvent / fuel
How can ethanol be manufactured by fermentation and what conditions are required? [4]
Fermentation of glucose / temperature around 30ᵒC / anaerobic conditions / yeast
Write the word and symbol equation for the fermentation of glucose to form ethanol [2]
Glucose → Ethanol + Carbon Dioxide C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂
How can ethanol be produced from ethene and what conditions are required? [4]
Ethene undergoes an addition reaction with steam / 300ᵒC / 60-70 atm / phosphoric acid catalyst
Write the word and symbol equation for the production of ethanol from ethene [2]
Ethene + Steam → Ethanol C₂H₄ + H₂O → C₂H₅OH
What are polymers? [2]
Large molecules / built from small units called monomers
How can polymers differ from each other? [2]
Different units / different linkages
How is polyethene made? [2]
Addition polymerisation / of ethene monomers
What is the difference between addition polymerisation and condensation polymerisation? [2]
Addition polymerisation forms a polymer from alkene monomers / condensation polymerisation forms a polymer by reacting compounds with two different functional groups together
