Boiling Points of Straight-Chain & Branched Chained Alkanes.

Name Molecular
Formula
Melting
Point
(oC)
Boiling
Point
(oC)
State at
25oC
methane CH4 -183 -164 gas
ethane C2H6 -183 -89 gas
propane C3H8 -190 -42 gas
butane C4H10 -138 -0.5 gas
pentane C5H12 -130 36 liquid
hexane C6H14 -95 69 liquid
heptane C7H16 -91 98 liquid
octane C8H18 -57 125 liquid
nonane C9H20 -51 151 liquid
decane C10H22 -30 174 liquid
undecane C11H24 -25 196 liquid
dodecane C12H26 -10 216 liquid
eicosane C20H42 37 343 solid
triacontane C30H62 66 450 solid

As the mass of the alkane increases so does the boiling point. 

Compound M.F. Boiling Point / K
Hexane C6H14 342
2-MethylPentane C6H14 333
3-MethylPentane C6H14 336
2,2-DiMethylButane C6H14 323
2,3-DiMethylButane C6H14 331