<Li> The change in enthalpy for a reaction can be calculated from the enthalpies of formation of the reactants and the products </Li> <Li> Elements in their standard states make no contribution to the enthalpy calculations for the reaction since the enthalpy of an element in its standard state is zero . Allotropes of an element other than the standard state generally have non-zero standard enthalpies of formation . </Li> <P> Thermochemical properties of selected substances at 298 K and 1 atm </P> <Table> <Tr> <Th> Species </Th> <Th> Phase </Th> <Th> Chemical formula </Th> <Th> Δ H / (kJ / mol) </Th> </Tr> <Tr> <Td_colspan="4"> Aluminium </Td> </Tr> <Tr> <Td> Aluminium </Td> <Td> Solid </Td> <Td> Al </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Aluminium chloride </Td> <Td> Solid </Td> <Td> AlCl </Td> <Td> − 705.63 </Td> </Tr> <Tr> <Td> Aluminium oxide </Td> <Td> Solid </Td> <Td> Al O </Td> <Td> − 1669.8 </Td> </Tr> <Tr> <Td> Aluminium hydroxide </Td> <Td> Solid </Td> <Td> Al (OH) </Td> <Td> − 1277 </Td> </Tr> <Tr> <Td> Aluminium sulphate </Td> <Td> Solid </Td> <Td> Al (SO) </Td> <Td> − 3440 </Td> </Tr> <Tr> <Td> Ammonia (ammonium hydroxide) </Td> <Td> aq </Td> <Td> NH (NH OH) </Td> <Td> − 80.8 </Td> </Tr> <Tr> <Td> Ammonia </Td> <Td> Gas </Td> <Td> NH </Td> <Td> − 46.1 </Td> </Tr> <Tr> <Td> Ammonium nitrate </Td> <Td> Solid </Td> <Td> NH NO </Td> <Td> − 365.6 </Td> </Tr> <Tr> <Td_colspan="4"> Barium </Td> </Tr> <Tr> <Td> Barium chloride </Td> <Td> Solid </Td> <Td> BaCl </Td> <Td> − 858.6 </Td> </Tr> <Tr> <Td> Barium carbonate </Td> <Td> Solid </Td> <Td> BaCO </Td> <Td> − 1213 </Td> </Tr> <Tr> <Td> Barium hydroxide </Td> <Td> Solid </Td> <Td> Ba (OH) </Td> <Td> − 944.7 </Td> </Tr> <Tr> <Td> Barium oxide </Td> <Td> Solid </Td> <Td> BaO </Td> <Td> − 548.1 </Td> </Tr> <Tr> <Td> Barium sulfate </Td> <Td> Solid </Td> <Td> BaSO </Td> <Td> − 1473.2 </Td> </Tr> <Tr> <Td_colspan="4"> Beryllium </Td> </Tr> <Tr> <Td> Beryllium </Td> <Td> Solid </Td> <Td> Be </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Beryllium hydroxide </Td> <Td> Solid </Td> <Td> Be (OH) </Td> <Td> − 902.9999 </Td> </Tr> <Tr> <Td> Beryllium oxide </Td> <Td> Solid </Td> <Td> BeO </Td> <Td> − 609.4 (25) </Td> </Tr> <Tr> <Td_colspan="4"> Boron </Td> </Tr> <Tr> <Td> Boron trichloride </Td> <Td> Solid </Td> <Td> BCl </Td> <Td> − 402.96 </Td> </Tr> <Tr> <Td_colspan="4"> Bromine </Td> </Tr> <Tr> <Td> Bromine </Td> <Td> Liquid </Td> <Td> Br </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Bromide ion </Td> <Td> Aqueous </Td> <Td> Br </Td> <Td> − 121 </Td> </Tr> <Tr> <Td> Bromine </Td> <Td> Gas </Td> <Td> Br </Td> <Td> 111.884 </Td> </Tr> <Tr> <Td> Bromine </Td> <Td> Gas </Td> <Td> Br </Td> <Td> 30.91 </Td> </Tr> <Tr> <Td> Bromine trifluoride </Td> <Td> Gas </Td> <Td> BrF </Td> <Td> − 255.60 </Td> </Tr> <Tr> <Td> Hydrogen bromide </Td> <Td> Gas </Td> <Td> HBr </Td> <Td> − 36.29 </Td> </Tr> <Tr> <Td_colspan="4"> Cadmium </Td> </Tr> <Tr> <Td> Cadmium </Td> <Td> Solid </Td> <Td> Cd </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Cadmium oxide </Td> <Td> Solid </Td> <Td> CdO </Td> <Td> − 258 </Td> </Tr> <Tr> <Td> Cadmium hydroxide </Td> <Td> Solid </Td> <Td> Cd (OH) </Td> <Td> − 561 </Td> </Tr> <Tr> <Td> Cadmium sulfide </Td> <Td> Solid </Td> <Td> CdS </Td> <Td> − 162 </Td> </Tr> <Tr> <Td> Cadmium sulfate </Td> <Td> Solid </Td> <Td> CdSO </Td> <Td> − 935 </Td> </Tr> <Tr> <Td_colspan="4"> Calcium </Td> </Tr> <Tr> <Td> Calcium </Td> <Td> Solid </Td> <Td> Ca </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Calcium </Td> <Td> Gas </Td> <Td> Ca </Td> <Td> 178.2 </Td> </Tr> <Tr> <Td> Calcium (II) ion </Td> <Td> Gas </Td> <Td> Ca </Td> <Td> 1925.90 </Td> </Tr> <Tr> <Td> Calcium carbide </Td> <Td> Solid </Td> <Td> CaC </Td> <Td> − 59.8 </Td> </Tr> <Tr> <Td> Calcium carbonate (Calcite) </Td> <Td> Solid </Td> <Td> CaCO </Td> <Td> − 1206.9 </Td> </Tr> <Tr> <Td> Calcium chloride </Td> <Td> Solid </Td> <Td> CaCl </Td> <Td> − 795.8 </Td> </Tr> <Tr> <Td> Calcium chloride </Td> <Td> Aqueous </Td> <Td> CaCl </Td> <Td> − 877.3 </Td> </Tr> <Tr> <Td> Calcium phosphate </Td> <Td> Solid </Td> <Td> Ca (PO) </Td> <Td> − 4132 </Td> </Tr> <Tr> <Td> Calcium fluoride </Td> <Td> Solid </Td> <Td> CaF </Td> <Td> − 1219.6 </Td> </Tr> <Tr> <Td> Calcium hydride </Td> <Td> Solid </Td> <Td> CaH </Td> <Td> − 186.2 </Td> </Tr> <Tr> <Td> Calcium hydroxide </Td> <Td> Solid </Td> <Td> Ca (OH) </Td> <Td> − 986.09 </Td> </Tr> <Tr> <Td> Calcium hydroxide </Td> <Td> Aqueous </Td> <Td> Ca (OH) </Td> <Td> − 1002.82 </Td> </Tr> <Tr> <Td> Calcium oxide </Td> <Td> Solid </Td> <Td> CaO </Td> <Td> − 635.09 </Td> </Tr> <Tr> <Td> Calcium sulfate </Td> <Td> Solid </Td> <Td> CaSO </Td> <Td> − 1434.52 </Td> </Tr> <Tr> <Td> Calcium sulfide </Td> <Td> Solid </Td> <Td> CaS </Td> <Td> − 482.4 </Td> </Tr> <Tr> <Td> Wollastonite </Td> <Td> Solid </Td> <Td> CaSiO </Td> <Td> − 1630 </Td> </Tr> <Tr> <Td_colspan="4"> Caesium </Td> </Tr> <Tr> <Td> Caesium </Td> <Td> Solid </Td> <Td> Cs </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Caesium </Td> <Td> Gas </Td> <Td> Cs </Td> <Td> 76.50 </Td> </Tr> <Tr> <Td> Caesium </Td> <Td> Liquid </Td> <Td> Cs </Td> <Td> 2.09 </Td> </Tr> <Tr> <Td> Caesium (I) ion </Td> <Td> Gas </Td> <Td> Cs </Td> <Td> 457.964 </Td> </Tr> <Tr> <Td> Caesium chloride </Td> <Td> Solid </Td> <Td> CsCl </Td> <Td> − 443.04 </Td> </Tr> <Tr> <Td_colspan="3"> Carbon </Td> </Tr> <Tr> <Td> Carbon (Graphite) </Td> <Td> Solid </Td> <Td> </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Carbon (Diamond) </Td> <Td> Solid </Td> <Td> </Td> <Td> 1.9 </Td> </Tr> <Tr> <Td> Carbon </Td> <Td> Gas </Td> <Td> </Td> <Td> 716.67 </Td> </Tr> <Tr> <Td> Carbon dioxide </Td> <Td> Gas </Td> <Td> CO </Td> <Td> − 393.509 </Td> </Tr> <Tr> <Td> Carbon disulfide </Td> <Td> Liquid </Td> <Td> CS </Td> <Td> 89.41 </Td> </Tr> <Tr> <Td> Carbon disulfide </Td> <Td> Gas </Td> <Td> CS </Td> <Td> 116.7 </Td> </Tr> <Tr> <Td> Carbon monoxide </Td> <Td> Gas </Td> <Td> CO </Td> <Td> − 110.525 </Td> </Tr> <Tr> <Td> Carbonyl chloride (Phosgene) </Td> <Td> Gas </Td> <Td> COCl </Td> <Td> − 218.8 </Td> </Tr> <Tr> <Td> Carbon dioxide (un--ionized) </Td> <Td> Aqueous </Td> <Td> CO (aq) </Td> <Td> − 419.26 </Td> </Tr> <Tr> <Td> Bicarbonate ion </Td> <Td> Aqueous </Td> <Td> HCO </Td> <Td> − 689.93 </Td> </Tr> <Tr> <Td> Carbonate ion </Td> <Td> Aqueous </Td> <Td> CO </Td> <Td> − 675.23 </Td> </Tr> <Tr> <Td_colspan="4"> Chlorine </Td> </Tr> <Tr> <Td> Monatomic chlorine </Td> <Td> Gas </Td> <Td> Cl </Td> <Td> 121.7 </Td> </Tr> <Tr> <Td> Chloride ion </Td> <Td> Aqueous </Td> <Td> Cl </Td> <Td> − 167.2 </Td> </Tr> <Tr> <Td> Chlorine </Td> <Td> Gas </Td> <Td> Cl </Td> <Td> 0 </Td> </Tr> <Tr> <Td_colspan="4"> Chromium </Td> </Tr> <Tr> <Td> Chromium </Td> <Td> Solid </Td> <Td> Cr </Td> <Td> 0 </Td> </Tr> <Tr> <Td_colspan="4"> Copper </Td> </Tr> <Tr> <Td> Copper </Td> <Td> Solid </Td> <Td> Cu </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Copper (II) oxide </Td> <Td> Solid </Td> <Td> CuO </Td> <Td> − 155.2 </Td> </Tr> <Tr> <Td> Copper (II) sulfate </Td> <Td> Aqueous </Td> <Td> CuSO </Td> <Td> − 769.98 </Td> </Tr> <Tr> <Td_colspan="4"> Fluorine </Td> </Tr> <Tr> <Td> Fluorine </Td> <Td> Gas </Td> <Td> </Td> <Td> 0 </Td> </Tr> <Tr> <Td_colspan="4"> Hydrogen </Td> </Tr> <Tr> <Td> Monatomic hydrogen </Td> <Td> Gas </Td> <Td> </Td> <Td> 218 </Td> </Tr> <Tr> <Td> Hydrogen </Td> <Td> Gas </Td> <Td> </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Water </Td> <Td> Gas </Td> <Td> H O </Td> <Td> − 241.818 </Td> </Tr> <Tr> <Td> Water </Td> <Td> Liquid </Td> <Td> H O </Td> <Td> − 285.8 </Td> </Tr> <Tr> <Td> Hydrogen ion </Td> <Td> Aqueous </Td> <Td> </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Hydroxide ion </Td> <Td> Aqueous </Td> <Td> OH </Td> <Td> − 230 </Td> </Tr> <Tr> <Td> Hydrogen peroxide </Td> <Td> Liquid </Td> <Td> H O </Td> <Td> − 187.8 </Td> </Tr> <Tr> <Td> Phosphoric acid </Td> <Td> Liquid </Td> <Td> H PO </Td> <Td> − 1288 </Td> </Tr> <Tr> <Td> Hydrogen cyanide </Td> <Td> Gas </Td> <Td> HCN </Td> <Td> 130.5 </Td> </Tr> <Tr> <Td> Hydrogen bromide </Td> <Td> Liquid </Td> <Td> HBr </Td> <Td> − 36.3 </Td> </Tr> <Tr> <Td> Hydrogen chloride </Td> <Td> Gas </Td> <Td> HCl </Td> <Td> − 92.30 </Td> </Tr> <Tr> <Td> Hydrogen chloride </Td> <Td> Aqueous </Td> <Td> HCl </Td> <Td> − 167.2 </Td> </Tr> <Tr> <Td> Hydrogen fluoride </Td> <Td> Gas </Td> <Td> HF </Td> <Td> − 273.3 </Td> </Tr> <Tr> <Td> Hydrogen iodide </Td> <Td> Gas </Td> <Td> HI </Td> <Td> 26.5 </Td> </Tr> <Tr> <Td_colspan="4"> Iodine </Td> </Tr> <Tr> <Td> Iodine </Td> <Td> Solid </Td> <Td> </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Iodine </Td> <Td> Gas </Td> <Td> </Td> <Td> 62.438 </Td> </Tr> <Tr> <Td> Iodine </Td> <Td> Aqueous </Td> <Td> </Td> <Td> 23 </Td> </Tr> <Tr> <Td> Iodide ion </Td> <Td> Aqueous </Td> <Td> </Td> <Td> − 55 </Td> </Tr> <Tr> <Td_colspan="4"> Iron </Td> </Tr> <Tr> <Td> Iron </Td> <Td> Solid </Td> <Td> Fe </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Iron carbide (Cementite) </Td> <Td> Solid </Td> <Td> Fe C </Td> <Td> 5.4 </Td> </Tr> <Tr> <Td> Iron (II) carbonate (Siderite) </Td> <Td> Solid </Td> <Td> FeCO </Td> <Td> − 750.6 </Td> </Tr> <Tr> <Td> Iron (III) chloride </Td> <Td> Solid </Td> <Td> FeCl </Td> <Td> − 399.4 </Td> </Tr> <Tr> <Td> Iron (II) oxide (Wüstite) </Td> <Td> Solid </Td> <Td> FeO </Td> <Td> − 272 </Td> </Tr> <Tr> <Td> Iron (II, III) oxide (Magnetite) </Td> <Td> Solid </Td> <Td> Fe O </Td> <Td> − 1118 </Td> </Tr> <Tr> <Td> Iron (III) oxide (Hematite) </Td> <Td> Solid </Td> <Td> Fe O </Td> <Td> − 824.2 </Td> </Tr> <Tr> <Td> Iron (II) sulfate </Td> <Td> Solid </Td> <Td> FeSO </Td> <Td> − 929 </Td> </Tr> <Tr> <Td> Iron (III) sulfate </Td> <Td> Solid </Td> <Td> Fe (SO) </Td> <Td> − 2583 </Td> </Tr> <Tr> <Td> Iron (II) sulfide </Td> <Td> Solid </Td> <Td> FeS </Td> <Td> − 102 </Td> </Tr> <Tr> <Td> Pyrite </Td> <Td> Solid </Td> <Td> FeS </Td> <Td> − 178 </Td> </Tr> <Tr> <Td_colspan="4"> Lead </Td> </Tr> <Tr> <Td> Lead </Td> <Td> Solid </Td> <Td> Pb </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Lead dioxide </Td> <Td> Solid </Td> <Td> PbO </Td> <Td> − 277 </Td> </Tr> <Tr> <Td> Lead sulfide </Td> <Td> Solid </Td> <Td> PbS </Td> <Td> − 100 </Td> </Tr> <Tr> <Td> Lead sulfate </Td> <Td> Solid </Td> <Td> PbSO </Td> <Td> − 920 </Td> </Tr> <Tr> <Td> Lead (II) nitrate </Td> <Td> Solid </Td> <Td> Pb (NO) </Td> <Td> − 452 </Td> </Tr> <Tr> <Td> Lead (II) sulfate </Td> <Td> Solid </Td> <Td> PbSO </Td> <Td> − 920 </Td> </Tr> <Tr> <Td_colspan="4"> Magnesium </Td> </Tr> <Tr> <Td> Magnesium </Td> <Td> Solid </Td> <Td> Mg </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Magnesium ion </Td> <Td> Aqueous </Td> <Td> Mg </Td> <Td> − 466.85 </Td> </Tr> <Tr> <Td> Magnesium carbonate </Td> <Td> Solid </Td> <Td> MgCO </Td> <Td> − 1095.797 </Td> </Tr> <Tr> <Td> Magnesium chloride </Td> <Td> Solid </Td> <Td> MgCl </Td> <Td> − 641.8 </Td> </Tr> <Tr> <Td> Magnesium hydroxide </Td> <Td> Solid </Td> <Td> Mg (OH) </Td> <Td> − 924.54 </Td> </Tr> <Tr> <Td> Magnesium hydroxide </Td> <Td> Aqueous </Td> <Td> Mg (OH) </Td> <Td> − 926.8 </Td> </Tr> <Tr> <Td> Magnesium oxide </Td> <Td> Solid </Td> <Td> MgO </Td> <Td> − 601.6 </Td> </Tr> <Tr> <Td> Magnesium sulfate </Td> <Td> Solid </Td> <Td> MgSO </Td> <Td> − 1278.2 </Td> </Tr> <Tr> <Td_colspan="4"> Manganese </Td> </Tr> <Tr> <Td> Manganese </Td> <Td> Solid </Td> <Td> Mn </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Manganese (II) oxide </Td> <Td> Solid </Td> <Td> MnO </Td> <Td> − 384.9 </Td> </Tr> <Tr> <Td> Manganese (IV) oxide </Td> <Td> Solid </Td> <Td> MnO </Td> <Td> − 519.7 </Td> </Tr> <Tr> <Td> Manganese (III) oxide </Td> <Td> Solid </Td> <Td> Mn O </Td> <Td> − 971 </Td> </Tr> <Tr> <Td> Manganese (II, III) oxide </Td> <Td> Solid </Td> <Td> Mn O </Td> <Td> − 1387 </Td> </Tr> <Tr> <Td> Permanganate </Td> <Td> Aqueous </Td> <Td> MnO − </Td> <Td> − 543 </Td> </Tr> <Tr> <Td_colspan="4"> Mercury </Td> </Tr> <Tr> <Td> Mercury (II) oxide (red) </Td> <Td> Solid </Td> <Td> HgO </Td> <Td> − 90.83 </Td> </Tr> <Tr> <Td> Mercury sulfide (red, cinnabar) </Td> <Td> Solid </Td> <Td> HgS </Td> <Td> − 58.2 </Td> </Tr> <Tr> <Td_colspan="4"> Nitrogen </Td> </Tr> <Tr> <Td> Ammonia </Td> <Td> Aqueous </Td> <Td> NH </Td> <Td> − 80.8 </Td> </Tr> <Tr> <Td> Ammonia </Td> <Td> Gas </Td> <Td> NH </Td> <Td> − 45.90 </Td> </Tr> <Tr> <Td> Ammonium chloride </Td> <Td> Solid </Td> <Td> NH Cl </Td> <Td> − 314.55 </Td> </Tr> <Tr> <Td> Nitrogen dioxide </Td> <Td> Gas </Td> <Td> NO </Td> <Td> 33.2 </Td> </Tr> <Tr> <Td> Nitrous oxide </Td> <Td> Gas </Td> <Td> N O </Td> <Td> 82.05 </Td> </Tr> <Tr> <Td> Nitric oxide </Td> <Td> Gas </Td> <Td> NO </Td> <Td> 90.29 </Td> </Tr> <Tr> <Td> Dinitrogen tetroxide </Td> <Td> Gas </Td> <Td> N O </Td> <Td> 9.16 </Td> </Tr> <Tr> <Td> Dinitrogen pentoxide </Td> <Td> Solid </Td> <Td> N O </Td> <Td> − 43.1 </Td> </Tr> <Tr> <Td> Dinitrogen pentoxide </Td> <Td> Gas </Td> <Td> N O </Td> <Td> 11.3 </Td> </Tr> <Tr> <Td_colspan="4"> Oxygen </Td> </Tr> <Tr> <Td> Monatomic oxygen </Td> <Td> Gas </Td> <Td> O </Td> <Td> 249 </Td> </Tr> <Tr> <Td> Oxygen </Td> <Td> Gas </Td> <Td> O </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Ozone </Td> <Td> Gas </Td> <Td> O </Td> <Td> 143 </Td> </Tr> <Tr> <Td_colspan="4"> Phosphorus </Td> </Tr> <Tr> <Td> White phosphorus </Td> <Td> Solid </Td> <Td> </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Red phosphorus </Td> <Td> Solid </Td> <Td> </Td> <Td>--17.4 </Td> </Tr> <Tr> <Td> Black phosphorus </Td> <Td> Solid </Td> <Td> </Td> <Td>--39.3 </Td> </Tr> <Tr> <Td> Phosphorus trichloride </Td> <Td> Liquid </Td> <Td> PCl </Td> <Td> − 319.7 </Td> </Tr> <Tr> <Td> Phosphorus trichloride </Td> <Td> Gas </Td> <Td> PCl </Td> <Td> − 278 </Td> </Tr> <Tr> <Td> Phosphorus pentachloride </Td> <Td> Solid </Td> <Td> PCl </Td> <Td> − 440 </Td> </Tr> <Tr> <Td_colspan="4"> Potassium </Td> </Tr> <Tr> <Td> Potassium bromide </Td> <Td> Solid </Td> <Td> KBr </Td> <Td> − 392.2 </Td> </Tr> <Tr> <Td> Potassium carbonate </Td> <Td> Solid </Td> <Td> K CO </Td> <Td> − 1150 </Td> </Tr> <Tr> <Td> Potassium chlorate </Td> <Td> Solid </Td> <Td> KClO </Td> <Td> − 391.4 </Td> </Tr> <Tr> <Td> Potassium chloride </Td> <Td> Solid </Td> <Td> KCl </Td> <Td> − 436.68 </Td> </Tr> <Tr> <Td> Potassium fluoride </Td> <Td> Solid </Td> <Td> KF </Td> <Td> − 562.6 </Td> </Tr> <Tr> <Td> Potassium oxide </Td> <Td> Solid </Td> <Td> K O </Td> <Td> − 363 </Td> </Tr> <Tr> <Td> Potassium perchlorate </Td> <Td> Solid </Td> <Td> KClO </Td> <Td> − 430.12 </Td> </Tr> <Tr> <Td_colspan="4"> Silicon </Td> </Tr> <Tr> <Td> Silicon </Td> <Td> Gas </Td> <Td> Si </Td> <Td> 368.2 </Td> </Tr> <Tr> <Td> Silicon carbide </Td> <Td> Solid </Td> <Td> SiC </Td> <Td> − 73.22 </Td> </Tr> <Tr> <Td> Silicon tetrachloride </Td> <Td> Liquid </Td> <Td> SiCl </Td> <Td> − 640.1 </Td> </Tr> <Tr> <Td> Silica (Quartz) </Td> <Td> Solid </Td> <Td> SiO </Td> <Td> − 910.86 </Td> </Tr> <Tr> <Td_colspan="4"> Silver </Td> </Tr> <Tr> <Td> Silver bromide </Td> <Td> Solid </Td> <Td> AgBr </Td> <Td> − 99.5 </Td> </Tr> <Tr> <Td> Silver chloride </Td> <Td> Solid </Td> <Td> AgCl </Td> <Td> − 127.01 </Td> </Tr> <Tr> <Td> Silver iodide </Td> <Td> Solid </Td> <Td> AgI </Td> <Td> − 62.4 </Td> </Tr> <Tr> <Td> Silver oxide </Td> <Td> Solid </Td> <Td> Ag O </Td> <Td> − 31.1 </Td> </Tr> <Tr> <Td> Silver sulfide </Td> <Td> Solid </Td> <Td> Ag S </Td> <Td> − 31.8 </Td> </Tr> <Tr> <Td_colspan="4"> Sodium </Td> </Tr> <Tr> <Td> Sodium </Td> <Td> Solid </Td> <Td> Na </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Sodium </Td> <Td> Gas </Td> <Td> Na </Td> <Td> + 107.5 </Td> </Tr> <Tr> <Td> Sodium bicarbonate </Td> <Td> Solid </Td> <Td> NaHCO </Td> <Td> − 950.8 </Td> </Tr> <Tr> <Td> Sodium carbonate </Td> <Td> Solid </Td> <Td> Na CO </Td> <Td> − 1130.77 </Td> </Tr> <Tr> <Td> Sodium chloride </Td> <Td> Aqueous </Td> <Td> NaCl </Td> <Td> − 407.27 </Td> </Tr> <Tr> <Td> Sodium chloride </Td> <Td> Solid </Td> <Td> NaCl </Td> <Td> − 411.12 </Td> </Tr> <Tr> <Td> Sodium chloride </Td> <Td> Liquid </Td> <Td> NaCl </Td> <Td> − 385.92 </Td> </Tr> <Tr> <Td> Sodium chloride </Td> <Td> Gas </Td> <Td> NaCl </Td> <Td> − 181.42 </Td> </Tr> <Tr> <Td> Sodium fluoride </Td> <Td> Solid </Td> <Td> NaF </Td> <Td> − 569.0 </Td> </Tr> <Tr> <Td> Sodium hydroxide </Td> <Td> Aqueous </Td> <Td> NaOH </Td> <Td> − 469.15 </Td> </Tr> <Tr> <Td> Sodium hydroxide </Td> <Td> Solid </Td> <Td> NaOH </Td> <Td> − 425.93 </Td> </Tr> <Tr> <Td> Sodium nitrate </Td> <Td> Aqueous </Td> <Td> NaNO </Td> <Td> − 446.2 </Td> </Tr> <Tr> <Td> Sodium nitrate </Td> <Td> Solid </Td> <Td> NaNO </Td> <Td> − 424.8 </Td> </Tr> <Tr> <Td> Sodium oxide </Td> <Td> Solid </Td> <Td> Na O </Td> <Td> − 414.2 </Td> </Tr> <Tr> <Td_colspan="4"> Sulfur </Td> </Tr> <Tr> <Td> Sulfur (monoclinic) </Td> <Td> Solid </Td> <Td> </Td> <Td> 0.3 </Td> </Tr> <Tr> <Td> Sulfur (rhombic) </Td> <Td> Solid </Td> <Td> </Td> <Td> 0 </Td> </Tr> <Tr> <Td> Hydrogen sulfide </Td> <Td> Gas </Td> <Td> </Td> <Td> − 20.63 </Td> </Tr> <Tr> <Td> Sulfur dioxide </Td> <Td> Gas </Td> <Td> SO </Td> <Td> − 296.84 </Td> </Tr> <Tr> <Td> Sulfur trioxide </Td> <Td> Gas </Td> <Td> SO </Td> <Td> − 395.7 </Td> </Tr> <Tr> <Td> Sulfuric acid </Td> <Td> Liquid </Td> <Td> H SO </Td> <Td> − 814 </Td> </Tr> <Tr> <Td_colspan="4"> Tin </Td> </Tr> <Tr> <Td_colspan="4"> Titanium </Td> </Tr> <Tr> <Td> Titanium </Td> <Td> Gas </Td> <Td> Ti </Td> <Td> 468 </Td> </Tr> <Tr> <Td> Titanium tetrachloride </Td> <Td> Gas </Td> <Td> TiCl </Td> <Td> − 763.2 </Td> </Tr> <Tr> <Td> Titanium tetrachloride </Td> <Td> Liquid </Td> <Td> TiCl </Td> <Td> − 804.2 </Td> </Tr> <Tr> <Td> Titanium dioxide </Td> <Td> Solid </Td> <Td> TiO </Td> <Td> − 944.7 </Td> </Tr> <Tr> <Td_colspan="4"> Zinc </Td> </Tr> <Tr> <Td> Zinc </Td> <Td> Gas </Td> <Td> Zn </Td> <Td> 130.7 </Td> </Tr> <Tr> <Td> Zinc chloride </Td> <Td> Solid </Td> <Td> ZnCl </Td> <Td> − 415.1 </Td> </Tr> <Tr> <Td> Zinc oxide </Td> <Td> Solid </Td> <Td> ZnO </Td> <Td> − 348.0 </Td> </Tr> <Tr> <Td> Zinc sulfate </Td> <Td> Solid </Td> <Td> ZnSO </Td> <Td> − 980.14 </Td> </Tr> </Table>

What is the enthalpy of formation of cao(s)