n-alkane, C27 C27 alkane, normal (i.e. straight-chain) isomer, common name: n-Heptacosane, formula : C27H56 Originally from the CUAHSI HIS VariableNameCV. See: http://his.cuahsi.org/mastercvreg/edit_cv11.aspx?tbl=VariableNameCV. ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables.