Topic 6 revision questions Flashcards
What are reagents and conditions are required to convert chloropropane to propene?
Concentrated potassium hydroxide
Ethanol as a solvent and heat
What is the reagent used to convert chloropropane to butane nitrile?
(contains a CN group)
KCN
Why is the reaction adds a CN group to a halogenoalkane used in industry?
Increases chain length
Why do alkenes have stereoisomers?
c=c double bond cannot rotate.
Features of stereoisomers.
Same molecular and structural formula.
Different arrangement of atoms
How do you identify an E isomer?
If atoms with highest molecular formula are on different sides of the molecule.
Difference between cis and trans isomers?
Cis - If the same group are on the same side of the molecule
trans - If the groups are on either side of the molecule
Why do larger hydrocarbons have higher boiling points?
Intermolecular forces are stronger.
What does cracking produce?
An alkene and an alkane
What is a use of alkenes?
Making plastics
What is thermal cracking and what are the conditions?
Use of high temperatures and pressures
750 degrees and 70 atm
What is catalytic cracking?
Lower temperature and pressure
Use zeolite catalyst
What is the process of reforming?
Converting unbranched hydrocarbons into branched hydrocarbons.
Branched hydrocarbons burn more efficiently in vehicle engines.
What can acid rain do?
Kill aquatic animals
Kill trees
What compounds cause acid rain?
Sulfur dioxide
Nitrogen oxides
What do catalytic converters do?
Convert harmful gases to water vapor and oxygen
What are the first and second ceramic blocks made out of in a catalytic converter?
1st - Platinum and rubidium
2nd - Platinum and Palladium
Benefit of the metals used in catalytic converters?
High melting points
Never rust
What do the microducts do in ceramic blocks?
Increase surface area
What happens to the proportion of branched alkanes and cyclic hydrocarbons?
They both increase
Why are tertiary carbocations more common than primary?
They are more stable
Alkyl groups push electrons towards it
What apparatus is needed for cracking in a lab?
Gas syringe
Ceramic fibre soaked in alkane
Aluminium oxide catalyst
Heat the middle of test tube
