c7: organic chemistry Flashcards
1
Q
what is observed when bromin water is added to an alkane
A
no colour change
remains orange
2
Q
what is observed when bromind water is added to an alkene
A
becomes colourless
3
Q
compare the structure and bonding of alkanes and alkenes
A
- both hydrocarbons
- both have covalent bonds
- both small molecules
- only alkenes have double c=c bond
(alkanes have c-c single bond)
4
Q
compare how alkenes and alkanes react
A
- both react w oxygen in complete combustion to produce water and co2
- alkene discolourises bromine water
- alkenes are more reactive
- alkenes can polymerise
5
Q
what conditions are needed to crack hydrocarbon molecules from diesel oil fraction
A
high temp
steam
catalyst
6
Q
ehy are large molecules cracked to produce smaller hydrocarbon molecules
A
smaller molecules are…
- more in demand
- more useful
- better fuels
- used to make alkenes and polymers
