alkanes Flashcards
1
Q
why do branched molecules have lower boiling points
A
there are weaker forces of attraction between branched molecules - prevents closer approach to neighbouring molecules.
2
Q
what happens when you add an alkane to water
A
forms 2 layers (insoluble)
3
Q
what conditions are needed for cracking
A
Over 400°c
moderate pressure
4
Q
method for reaction of hexane with bromine
A
- 1cm3 hexane in 2 text tubes
- 1 drop of bromine to each
- leave on in sunlight or UV
- wrap foil around the other
- leave for 5-10 minutes
- hold a glass rod dipped in concentrated ammonia solution so that gas blows across the top of each tube
5
Q
% error =
A
error on equipment x times used
———————————————- x 100
measurement taken
6
Q
which equipment has an error x 2
A
balance
burette
