3.2 and 3.3 I can recall the general formula and displayed formulae of alkanes

What is the general formula for alkanes? 
      C_n H_2n+2
Describe and explain the trend in boiling points:
The boiling points goes up as the chain length increases. This happens because it is harder to break the molecular forces of the bonds.

Name of Alkane	Chemical Formula	Boling Point (oc)	State at room temperature
Methane	C2H6	-89	gas
Ethane	C2H6	-89	gas
Propane	C3H8	-42	gas
Butane	C4H10	0	gas
Pentane	C5H12	36	liquid