1) Chemical formula for propane is CH₃-CH₂-CH₃. Propane is a three carbon alkane (acyclic saturated hydrocarbon). 2) Chemical formula for propanal is CH₃-CH₂-CH=O. Propanal is a saturated three carbon aldehyde (have a carbonyl center). 3) Chemical formula for propanol is CH₃-CH₂-CH₂-OH. 1-propanol is a primary alcohol. 4) Chemical formula for propanone is (CH₃)₂-C=O. Propanone or acetone is he simplest and smallest ketone.