Have you omitted part of the problem? If you are referring to "this" compound as the new compound, I would think pentane. If you are referring to the original compound, you haven't provided enough information.
http://www.elmhurst.edu/~chm/vchembook/501hcboilingpts.html
I would expect a 5 C chain.
The boiling point of another member of this homologous series was found to be 309 K. What is the likely molecular formula for this compound?
How many carbon atoms would you expect this new compound to have if its boiling point is between that of a four-carbon alkane and that of a six-carbon alkane?
2 answers
C5H12