Question

Place these hydrocarbons in order of decreasing boiling point:
paraffin :
methane:
octane:
isooctane: ( also known as 2,2,4 trimethylpentane)
octadecane:

Answer 1

bp increases with increasing mol mass.

So you want them highest molmass to lowest.

Answer 2

paraffin, octadecane, octane, isooctane, methane

Answer 3

paraffin, octadecane, isooctane, pentane, methan