Name the following hydrocarbons

1) Pentane       2) 2-Pentene

Explanation:

Both molecules have five carbons so you will add thhe prefix "pent-" and the first molecule only has single bonds so it will end in "-ane" because is it an Alkane. The second hydrocarbon has a double bond; therefore, it's a Alkene resulting in the ending of "-ene". BUT the double bond is located on the second carbon; therefore you must add "2-" before the name.