| Octan amonný | C2H7NO2 | CH3COONH4 | Mr = 77,084 |
| Octan draselný | CH3COOK | Mr = 98,143 | |
| Octan měďnatý - monohydrát | (CH3COO)2Cu.H2O | Mr = 199,651 | |
| Octan nikelnatý | (CH3COO)2Ni | Mr = 176,78 | |
| Octan olovnatý | (CH3COO)2Pb | Mr = 325,3 | |
| Octan sodný | CH3COONa | Mr = 82,035 | |
| Octová kyselina (ethanová kyselina) | C2H4O2 | CH3COOH | Mr = 60,053 |
| 9-Oktadecenová kyselina | C18H34O2 | CH3(CH2)7-CH=CH-(CH2)7-COOH | Mr = 282,468 |
| Oktadecyl-vinylether (oktadekoxyethen) |
C20H40O | CH3(CH2)17-O-CH=CH2 | Mr = 296,538 |
| Oktadekanová kyselina | viz Stearová kyselina | ||
| Oktakarbonyl dikobaltu | [Co2(CO)8] | Mr = 341,950 | |
| Oktan | C8H18 | CH3(CH2)6CH3 | Mr = 114,231 |
| Oktanal (kaprylaldehyd) | C8H16O | CH3(CH2)6-CH=O | Mr = 128,215 |
| 1-Oktanol (oktylalkohol) | C8H18O | CH3(CH2)7-OH | Mr = 130,231 |
| 2-Oktanol (sek. oktylalkohol) | C8H18O | Mr = 130,231 | |
| Oktanová kyselina (kaprylová kys.) | C8H16O2 | CH3(CH2)6-COOH | Mr = 144,214 |
| 1-Okten | C8H16 | CH3(CH2)5-CH=CH2 | Mr = 112,216 |
| 2-Okten | C8H16 | CH3(CH2)4-CH=CH-CH3 | Mr = 112,216 |
| 3-Okten | C8H16 | CH3(CH2)3-CH=CH-CH2CH3 | Mr = 112,216 |
| 4-Okten | C8H16 | CH3CH2CH2-CH=CH-CH2CH2CH3 | Mr = 112,216 |
| 1-Oktin (hexylacetylen) | C8H14 | CH3(CH2)5-C |
Mr = 110,200 |
| 2-Oktin | C8H14 | CH3(CH2)4-C |
Mr = 110,200 |
| 3-Oktin | C8H14 | CH3(CH2)3-C |
Mr = 110,200 |
| 4-Oktin | C8H14 | CH3CH2CH2-C |
Mr = 110,200 |
| Oktyl-vinylether | C10H20O | CH3(CH2)7-O-CH=CH2 | Mr = 156,269 |
| Olejová kyselina | viz cis-9-Oktadecenová kyselina | ||
| Oxalodonitril | viz Dikyan | ||
| Oxan | viz Tetrahydropyran | ||
| Oxetan (trimethylenoxid) | C3H6O | ![]() |
Mr = 58,080 |
| Oxid antimoničný | Sb2O5 | Mr = 323,50 | |
| Oxid antimonitý | Sb2O3 (Sb4O6) | Mr = 291,50 | |
| Oxid arseničný | As2O5 (As4O10) | Mr = 229,840 | |
| Oxid arsenitý (arsenik) | As4O6 | Mr = 395,683 | |
| Oxid barnatý | BaO | Mr = 153,33 | |
| Oxid beryllnatý | BeO | Mr = 25,012 | |
| Oxid bismutičný | Bi2O5 | Mr = 497,958 | |
| Oxid bismutitý | Bi2O3 | Mr = 465,959 | |
| Oxid boritý | B2O3 | Mr = 69,620 | |
| Oxid ceričitý | CeO2 | Mr = 172,12 | |
| Oxid cínatý | SnO | Mr = 134,69 | |
| Oxid cíničitý | SnO2 | Mr = 150,69 | |
| Oxid draselný | K2O | Mr = 94,195 | |
| Oxid dusičitý | NO2 (N2O4) | Mr = 46,006 | |
| Oxid dusičný | N2O5 | Mr = 108,010 | |
| Oxid dusitý | N2O3 | Mr = 76,012 | |
| Oxid dusnatý | NO | Mr = 30,006 | |
| Oxid dusný (azooxid) | N2O | Mr = 44,013 | |
| Oxid fosforečný | P4O10 | Mr = 283,889 | |
| Oxid fosforitý | P4O6 (P2O3) | Mr = 219,891 | |
| Oxid germaničitý | GeO2 | Mr = 104,59 | |
| Oxid hafničitý | HfO2 | Mr = 210,49 | |
| Oxid hlinitý | Al2O3 | Mr = 101,961 | |
| Oxid hořečnatý | MgO | Mr = 40,304 | |
| Oxid chloričitý | ClO2 | Mr = 67,452 | |
| Oxid chloristý | Cl2O7 | Mr = 182,902 | |
| Oxid chlorný | Cl2O | Mr = 86,905 | |
| Oxid chromičitý | CrO2 | Mr = 83,995 | |
| Oxid chromitý | Cr2O3 | Mr = 151,990 | |
| Oxid chromový | CrO3 | Mr = 99,994 | |
| Oxid jodičný | I2O5 | Mr = 333,806 | |
| Oxid kademnatý | CdO | Mr = 128,40 | |
| Oxid kobaltnato-kobaltitý | Co3O4 | Mr = 240,797 | |
| Oxid kobaltnatý | CoO | Mr = 74,933 | |
| Oxid křemičitý | SiO2 | Mr = 60,085 | |
| Oxid lanthanitý | La2O3 | Mr = 325,809 | |
| Oxid lithný | Li2O | Mr = 29,881 | |
| Oxid manganatý | MnO | Mr = 70,937 | |
| Oxid manganatý-oxid manganičitý (2:1) (tetraoxid trimanganu) |
Mn3O4 | Mr = 228,812 | |
| Oxid manganičitý | MnO2 | Mr = 86,937 | |
| Oxid manganistý | Mn2O7 | Mr = 221,872 | |
| Oxid manganitý | Mn2O3 | Mr = 157,874 | |
| Oxid měďnatý | CuO | Mr = 79,545 | |
| Oxid měďný | Cu2O | Mr = 143,091 | |
| Oxid molybdeničitý | MoO2 | Mr = 127,94 | |
| Oxid molybdenový | MoO3 | Mr = 143,94 | |
| Oxid nikelnatý | NiO | Mr = 74,69 | |
| Oxid niobičitý | NbO2 | Mr = 124,905 | |
| Oxid niobičný | Nb2O5 | Mr = 265,810 | |
| Oxid niobnatý | NbO | Mr = 108,906 | |
| Oxid olovičitý | PbO2 | Mr = 239,2 | |
| Oxid olovnatý | PbO | Mr = 223,2 | |
| Oxid olovnatý-oxid olovičitý (2:1) | Pb3O4 | Mr = 685,6 | |
| Oxid osmičelý | OsO4 | Mr = 254,2 | |
| Oxid palladnatý | PdO | Mr = 122,4 | |
| Oxid platičitý | PtO2 | Mr = 227,09 | |
| Oxid platnatý | PtO | Mr = 211,09 | |
| Oxid rheničitý | ReO2 | Mr = 218,206 | |
| Oxid rheniový | ReO3 | Mr = 234,205 | |
| Oxid rhenistý | Re2O7 | Mr = 484,410 | |
| Oxid rhoditý | Rh2O3 | Mr = 253,810 | |
| Oxid rtuťnatý | HgO | Mr = 216,59 | |
| Oxid rutheničelý | RuO4 | Mr = 165,07 | |
| Oxid rutheničitý | RuO2 | Mr = 133,07 | |
| Oxid samaritý | Sm2O3 | Mr = 348,7 | |
| Oxid seleničitý | SeO2 | Mr = 110,96 | |
| Oxid selenový | SeO3 | Mr = 126,96 | |
| Oxid sírový | SO3 | Mr = 80,064 | |
| Oxid siřičitý | SO2 | Mr = 64,065 | |
| Oxid sodný | Na2O | Mr = 61,979 | |
| Oxid strontnatý | SrO | Mr = 103,62 | |
| Oxid stříbrnatý (peroxid stříbrný) | AgO (Ag2O2) | Mr = 123,867 | |
| Oxid stříbrno-stříbřitý | AgIAgIIIO2 | Mr = 247,735 | |
| Oxid stříbrný | Ag2O | Mr = 231,735 | |
| Oxid stříbřitý | Ag2O3 | Mr = 263,734 | |
| Oxid tantaličný | Ta2O5 | Mr = 441,893 | |
| Oxid telluričitý | TeO2 | Mr = 159,60 | |
| Oxid tellurový | TeO3 | Mr = 175,60 | |
| Oxid thoričitý | ThO2 | Mr = 264,037 | |
| Oxid titanatý | TiO | Mr = 63,88 | |
| Oxid titaničitý (titanová běloba) | TiO2 | Mr = 79,88 | |
| Oxid titanitý | Ti2O3 | Mr = 143,76 | |
| Oxid uhelnatý | CO | Mr = 28,010 | |
| Oxid uhličitý | CO2 | Mr = 44,010 | |
| Oxid uraničitý | UO2 | Mr = 270,028 | |
| Oxid uraničitý-oxid uranový (2:1) | U3O7 | Mr = 826,083 | |
| Oxid uraničitý-oxid uranový (1:2) | U3O8 | Mr = 842,082 | |
| Oxid uranový | UO3 | Mr = 286,027 | |
| Oxid vanadičitý | VO2 (V2O4) | Mr = 82,940 | |
| Oxid vanadičný | V2O5 | Mr = 181,880 | |
| Oxid vanaditý | V2O3 | Mr = 149,881 | |
| Oxid vanadnatý | VO | Mr = 66,941 | |
| Oxid vápenatý | CaO | Mr = 56,08 | |
| Oxid wolframový | WO3 | Mr = 231,85 | |
| Oxid yttritý | Y2O3 | Mr = 225,810 | |
| Oxid zinečnatý (zinková běloba) | ZnO | Mr = 81,39 | |
| Oxid zirkoničitý | ZrO2 | Mr = 123,22 | |
| Oxid zlatitý | Au2O3 | Mr = 441,931 | |
| Oxid železitý | Fe2O3 | Mr = 159,692 | |
| Oxid železnato-železitý | Fe3O4 | Mr = 231,539 | |
| Oxid železnatý | FeO | Mr = 71,846 | |
| Oxiran (ethylenoxid, epoxyethan) |
C2H4O | Mr = 44,053 | |
| Oxiranylmethylakrylát (glycidylakrylát) |
C6H8O3 | Mr = 128,128 | |
| Oxiranylmethylmethakrylát (glycidylmethakrylát) |
C7H10O3 | Mr = 142,155 | |
| Oxolan | viz Tetrahydrofuran | ||
| 2-Oxolanylmethanol (tetrahydrofurfurylalkohol) |
C5H10O2 | ![]() |
Mr = 102,134 |
| 2-Oxopropanová kyselina | viz Pyrohroznová kyselina | ||
| 2,2'-Oxydiethanol | viz Diethylenglykol | ||