180 



TABLE 173.— HEATS OF COMBUSTION OF SOME CARBON COMPOUNDS" 



Given in kg calis at constant pressure per gram-molecular weight in vacuo. When retcrred 

 to constant volume the values should be 0.58 kg calm smaller (at about 18°C) for each condensed 

 gaseous molecule. Combustion products are C0 2 , liquid H 2 0, etc. Benzoic acid was adopted at 

 Lyons as a primary standard, its heat of combustion, 6324 g cahs per gram in air, 6319 in vacuo. 

 This is tacitly assumed as heat of isothermal combustion at 20°C. In absolute joules, 26,466 and 

 26,445 respectively. The following ratios may be taken as standard : Naphthalene/benzoic acid = 

 1.5201 (air); benzoic acid/sucrose = 1.6028 (air); naphthalene/sucrose = 2.4364 (air). 



For- 



Compound mula 



Isobutane (g) C 4 H 10 



n-Hexane Cr.Hu 



n-Heptane C-H 16 



n-Octane CsH^ 



Decane C10H22 



Hexadecane (s) CiuHjm 



Eicosane (s) C00H42 



Amylene C5H10 



Hexylene Co.H 12 



Acetylene (g) OH- 



Allylene (g) OH 4 



Trimethylene (g) .... OH 



Benzene C«Hn 



Naphthalene (s) CmH« 



Methyl-chloride (g) . . . CH3CI 



Methylene-chloride (v) CH 2 C1 2 



Chloroform (1) CHCI3 



(v)., " 



Carbon-tetrachloride 



(1) ecu 



Carbon-tetrachloride 



(v) " 



Carbon di-sulfide (I) . . CS 2 



" (v).. " 



Allyl alcohol OH n O 



Formaldehyde (g) . . . CH.O 



Acetone (v) O.H.O 



Camphor (s) C 10 H 18 O 



Sucrose: cane (s) . . , . Ci 2 H 22 Oii 

 milk (s), 



anhd 



malt (s) . . . . " 



Molec- 

 ular 

 weight 



58 



86.11 

 100.13 

 114.14 

 142.18 

 226.27 

 282.34 



70 



84.10 



26.02 



40 



42 



78.05 

 128.06 



50.5 



85.0 

 119.5 



154.0 



76.0 



58.05 



30.02 



58 



152.13 



342.18 



kg calm 

 per 



g mol 



683.4 



990.6 



1143.6 



1304.2 



1610.2 



2559.1 



3183.1 



803.4 



952.6 



312.0 



469 



496.8 



782.8 



1231.4 



168.7 



106.8 



89.2 



70.3 



37.3 



44.5 

 394.5 

 246.6 

 442.4 

 134.1 

 435.8 



1411 



1349.6 



1350.8 

 1351 



For- 

 Compound mula 



Starch 



Glycogen 



Cellulose 



Formic acid CHo0 2 



Acetic " C 2 H«0 2 



Propionic acid Cr.H 6 2 



n-butyric " C 4 H 8 2 



n-valeric " CbH 10 O 2 



Palmitic " (s) . . . . Ci 8 H3 2 2 



Stearic " (s) . . . . CikH 36 2 



Lactic " (s) C-HflOa 



Aniline OH7O 



Urea (s) CH 4 N s O 



Nicotine C in H 14 N 2 



Cyanogen (g) ON- 



Trinitrotoluene (s) . . . OHsNaOe 



n-propyl " OH s O 



n-butyl " OH 10 O 



n-heptyl " C T H 10 O 



Octyl " C s H 18 



Cetyl " (s)... CjoHmO 



Menthol (s) OoHonO 



Phenoi (s) C 6 H O 



Thymol C10H14O 



Dimethyl ether (g) . C 2 H 6 



Methylethyl " (v) . C 3 H 8 



Diethyl " (v). C«H, O 



53 Karasch, Nat. Bur. Standards Journ. Res., vol. 2, p. 359, 1929. 



TABLE 174.— HEATS OF COMBUSTION OF MISCELLANEOUS COMPOUNDS 



Calories 

 per g 



Substance substance 



Asphalt 9530 



Butter 9200 



Carbon : amorphous 8080 



charcoal 8100 



diamond 7860 



graphite 7900 



Copper (to CuO) 590 



Dynamite, 75% 1290 



Egg, white of 5700 



Egg, yolk of 8100 



Fats, animal 9500 



Hemoglobin 5900 



Hydrogen 33900 



Iron (to Fe 2 3 ) 1582 



Magnesium (to MgO) 6080 



Oils : cotton-seed 9500 



lard 9300 



olive 9400 



Calories 

 per g 



Substance substance 



Oils: 



petroleum : 



crude 11500 



light 10000 



heavy 10200 



rape 9500 



sperm 10000 



Paraffin (to C0 2 , H 2 1) 11140 



Paraffin (to CO., H 2 g) 10340 



Pitch 8400 



Sulfur, rhombic 2200 



Sulfur, monoclinic 2240 



Tallow 9500 



Woods: beech, 13% H 2 4170 



birch, 12% H 2 4210 



oak, 13% H 2 3990 



pine, 12% H 2 4420 



SMITHSONIAN PHYSICAL TABLES 



