alkanes Flashcards
why do branched molecules have lower boiling points
there are weaker forces of attraction between branched molecules - prevents closer approach to neighbouring molecules.
what happens when you add an alkane to water
forms 2 layers (insoluble)
what conditions are needed for cracking
Over 400°c
moderate pressure
zeolite catalyst
% error =
error on equipment x times used
———————————————- x 100
measurement taken
which equipment has an error x 2
balance
burette
define hydrocarbon
compounds containing hydrogen and carbon only
what does an empirical formula show
simplest whole number ratio of atoms present in the molecule
what does a molecular formula show
number of each type of atom present in the molecule
what does structural formula show
functional groups and how the atoms are bonded together
what does displayed formula show
shows all the bonds and all the atoms and how they are bonded
what does skeletal formula show
does not show C atoms or C-H bonds
define structural isomerism
occurs when two or more compounds have the same molecular formula but different structural formulae
define chain isomers
a type of structural isomer
they have a different arrangement of the carbon chain but the same molecular formula
why does boiling point increase with increasing chain length
more carbon atoms more electrons so stronger london forces
require more energy to overcome
how does branching affect boiling point
branching reduces the boiling point