F322 Flashcards
What is a homologous series?
A series of organic compounds with the same functional group, but each successive member differing by CH2.
What is a functional group?
A group of atoms responsible for the characteristic reactions of a compound.
What is E/Z isomerism?
Stereoisomerism caused by restricted rotation about a carbon - carbon double bond, where each of those carbons has has two different groups attached to them.
Note: not functional groups.
What is cis/trans isomerism?
A special case of E/Z isomerism where there is a hydrogen atom and a non hydrogen group attached to each carbon in the double bond.
What is homolytic fission?
Fission of a covalent bond to form two radicals.
What is heterolytic fission?
Fission of a covalent bond to form a cation and anion.
What is an electrophile?
An electron pair acceptor.
Name and show two methods of producing ethanol.
Fermentation of glucose. Glucose is converted to ethanol and CO2 by enzymes in yeast. This is an anaerobic process. Enzymes stop functioning when ethanol concentration > 15%.
C6H12O6 —–> 2C2H5OH + 2CO2
Reaction of ethene with steam with a phosphoric acid catalyst (H3PO4).
What is a nucleophile?
An electron pair donor.
State the mechanism and conditions for: an alkane to a halogenoalkane.
Mechanism: free radical substitution.
Conditions: UV light, halogen, room temperature and pressure.
State the mechanism and conditions for: an alkene to a halogenoalkane.
Mechanism: electrophilic addition.
Conditions: HX, room temperature and pressure.
State the mechanism and conditions for: halogenoalkane to an alcohol.
Mechanism: nucleophilic substitution.
Conditions: Heat with dilute aqueous alkali (nucleophile :OH).
What is the catalyst for addition polymerisation?
Ziegler-Natta catalyst.
State the type of reaction and conditions for: an alkene to an alcohol.
Type: Addition.
Conditions: steam, heated phosphoric acid catalyst, H3PO4, under pressure.
State the mechanism and conditions for: a halogenoalkane to an amine.
Mechanism: nucleophilic substitution.
Conditions: Heat under pressure with ethanolic ammonia.
What are the conditions to make an alkane from an alkene.
Hydrogen, 150 degrees and a nickel catalyst.
Name 3 methods of carbon capture AND storage.
- Store in geological formations / partially filled oil wells.
- Store deep in the oceans.
- React with metal oxides to form metal carbonates.
What is the mechanism and what are the reagents to convert ethene to bromoethane?
Mechanism: Electrophilic addition.
Reagent: hydrogen bromide.
How is a halogenoalkane formed from an alcohol?
Mechanism: substitution.
Reagents: HX (made from concentrated H2SO4 and NaX).
How is an alkene formed from an alcohol?
A dehydration reaction with a concentrated H2SO4 catalyst. Water and an alkene are formed.
Define average bond enthalpy.
Enthalpy change when one mole of gaseous covalent bonds is broken.
Why is it difficult to measure the enthalpy change of reaction from average bond enthalpy values?
The actual bond enthalpies may not be the same as the average bond enthalpies.
Give 3 reasons why catalysts are used in industry.
- They enable reactions to produce less toxic waste products.
- They allow reactions to happen at lower temperatures - reduces energy costs and reduces CO2 emissions.
- They enable reactions to take place with a higher atom economy.
Name disadvantages and advantages to using biofuels.
- Biofuels are renewable, fossil fuels are finite.
- Less land can be us d to grow crops.
- Deforestation may occur to provide farming land.
- Carbon neutral.
