According to our activity,
a.) In Alkanes (table 1)
Methane, Ethane,Propane,Butane are in gas state.
Pentene,Hexane,Heptane, and Octane are in a liquid state.
b.) in alkenes (table 2)
Ethene, propane, 1-butane are in a gas state.
1-pentene and 1-hexene are in liquid state.
c.) in Alkynes (table 3)
Ethyne, propyne, and 2-butane are in gas state, while Pentyne are in liquid state.
Observed Number of carbon atoms:
Alkanes - form single bonds with other carbon atoms.
Alkenes - form a double bonds between carbon atoms.
Alkynes - form triple bonds between carbon atoms.
boiling points of alkanes, alkenes, alkynes refer to their structure. their temperature in which substance goes from liquid to gas phase.
as you observed, when the molecule interacts less with each other it is likely to form a gaseous state often for those small structures.
when the molecule closely interacts with each other it is likely to form a liquid state often for those bigger structures.