(Heteroatom complications Heteroatoms are considered anything other than C or H. Halogens These simply substitute for hydrogens in the molecular formula. Therefore just like C2H6 is saturated,so is C2HF2. Oxygen CH3-CH3 is saturated(C2H) CH-O-CH is also saturated(C2HO) An oxygen can be added without requiring any additional hydrogens,so ignore the number of oxygens when calculating elements of Unsaturation. Nitrogen Nitrogen is trivalent,and when it replaces a C in a chain it requires only one hydrogen (-NH-vs.-CH2-),so nitrogens count as half a carbon Thus C.HoN is equivalent to CasHo.(i.e.one element of Unsaturation).) Ch07 Alkenes:Struct synth (landscape) Page 5 Ch07 Alkenes; Struct + synth (landscape) Page 5 (Heteroatom complications Heteroatoms are considered anything other than C or H. Halogens These simply substitute for hydrogens in the molecular formula. Therefore just like C2H6 is saturated, so is C2H4F2. Oxygen CH3-CH3 is saturated (C2H6) CH3-O-CH3 is also saturated (C2H6O) An oxygen can be added without requiring any additional hydrogens, so ignore the number of oxygens when calculating elements of Unsaturation. Nitrogen Nitrogen is trivalent, and when it replaces a C in a chain it requires only one hydrogen (-NH- vs. -CH2- ), so nitrogens count as half a carbon. Thus C4H9N is equivalent to C4.5H9. (i.e. one element of Unsaturation).)