3.3 - Organic Intro, Alkanes & Haloalkanes Flashcards
What is structural isomerism?
molecules with same molecular formula but different structure
What is stereoisomers?
molecules with same structural formula but atoms have different spatial arrangement
Which catalyst Is used in the catalytic cracking of alkanes
Zeolite
Why do E-Z isomers form?
Because there is restricted rotation around the C=C double bond
Describe thermal cracking
- high temperature & pressure
- produces a high % of alkenes
Describe catalytic cracking
- slight pressure
- high temperature
- in the presence of a zeolite catalyst (larger SA)
- used mainly to produce motor fuels & aromatic hydrocarbons
What are economic reasons for cracking alkanes
- fractions with shorter C chains are in more demand than larger fractions
- longer hydrocarbons are cracked into smaller more useful ones
- the products of cracking are more valuable
What is incomplete combustion & what products are formed (alkanes)
Combustion in a limited supply of O2
CO - carbon monoxide (poisonous)
soot (global dimming)
What type of hydrocarbons are most likely to undergo incomplete combustible
Longer chains
What do catalytic converters catalyse (equations)
2CO(g) + 2NO (g) —> N2 (g) + 2CO2 (g)
hydrocarbons + NO —> N2 + CO2 + H20
What is the ozone layers function?
To protect the Earth from harmful exposure to too many UV rays
How do CFCs break the ozone layer down? 
Free radical substitution 
What’s the difference between nucleophilic substitution and elimination ( both have OH)
NS: OH acts as a nucleophile
Elimination: OH acts as a base (proton accepter) + makes water
How is ozone beneficial
It absorbs harmful UV radiation
How are chlorine atoms formed in the upper atmosphere
When UV radiation causes C-Cl bonds in CFCs to break
What contributes to ozone layer depletion
Chlorine atoms catalyse the decomposition of ozone and contribute to the hole in the ozone layer
What is a nuclophile?
An electron pair donor
What is an electrophile?
An electron pair acceptor
Explain why a very thin layer of metals are used in catalytic converter
- to reduce amount of metals needed
- increase surface area
What is a racemic mixture ?
A mixture of equal amounts of enantiomers
What is the danger of using KCN?
It is water reactive and can produce HCN gas which is toxic and flammable
Describe optical isomerism
- a type of stereoisomerism
- chiral = cannot be superimposed on eachother
Explain how oxides of nitrogen are formed in engines
Reaction of nitrogen and oxygen from the air at high temperatures
Why are oxides of nitrogen emissions from vehicles bad?
Formation of acid rain
