Which is the material with the lowest heat

List of specific heat capacities




specific heat capacity selected fabrics

in the NIST Chemistry WebBook one can find further polynomial approaches for different substances (including standard entropy and standard enthalpy)

Solids

material spec. Heat cap. in J / (g K)
aluminum 0,896
antimony 0,209
concrete 0,879
lead 0,129
chrome 0,452
ice 1,377 - 2,1
Pure iron 0,439
Iron alloy (steel) 0,477
Iron (cast) 0,46 - 0,54
Glass 0,6 - 0,8
gold 0,130
Carbon diamond 0,472
Carbon graphite 0,715
copper 0,381
Copper alloy (brass) 0,389
magnesium 1,034
Nickel silver 0,393
nickel 0,444
paraffin 2,094
platinum 0,134
chocolate 3,140
Expanded polystyrene 1,200
silver 0,234
silicon 0,741
wax 2,931
tungsten 0,134
cement 0,754
zinc 0,389
tin 0,230

liquids

material spec. Heat cap. in J / (g K) formula
Ethanol 2,428 C.2H5OH
Acetone 2,160 C.3H6O
benzene 1,738 C.6H6
bromine 0,266
acetic acid 2,031 C.2H4O2
glycerin 2,428 C.3H8O3
Machine oil 1,675 -
Methanol 2,470 CH4O
Nitrobenzene 1,507 C.6H5O2N
mercury 0,139 Ed
nitric acid 1,717 ENT3
sulfuric acid 1,386 H2SO4
Turpentine oil 1,800 C.10H16
Trichloromethane 0,950 CHCl3
Water, at 20 ° C (material data see here) 4,187 H2O

Temperature dependence of the "molar heat" Cp with water

With the relationship:

the heat capacities of water can be calculated in the temperature range 273 K - 473 K (0-200 ° C). The unit [J / (mol K)] can easily be converted into the technical unit [J / (g K)] by dividing it by the molar mass [g / mol].

Temperature dependence of Cp with liquids

material mol. Mass in g / mol ** a ** *** b *** *** c *** *** d *** *** e *** *** f *** C.p (25 ° C) [J / (molK)] C.p (25 ° C) [J / (g K)]
Water (liquid) 18,02 855,0 ‘-1047 559,6 ‘-149,0 19,71 '-1,032 75,1 4,17

(Note: the underlying measurement data were recorded in 5K steps, measurement> 100 ° C in a pressure-tight measuring cell. At 30–50 ° C a pronounced Cp-Anomaly registered, the 25 ° C value is calculated; If parameters are inserted into the equation, they do not result in correct values ​​-> any parameter mixed up?

Temperature in ° C 0 10 20 40 60 70 80 90 100
c in J / (gK) 4,22 4,19 4,18 4,18 4,18 4,19 4,20 4,21 4,22

Gases

material formula spec. Heat cap. in J / (g K)
ammonia NH3 2,060
Ethylene C.2H4 1,465
acetylene C.2H2 1,641
chlorine Cl2 0,502
Hydrogen chloride HCl 0,799
air 0.78N2 + 0.2102 + 0.01Ar 1,0054
neon No 1,030
Sulfur dioxide SO2 0,632
Hydrogen sulfideH2S. 1,105
Nitric oxide NO 1,009

Temperature dependence of the "molar heat" Cp

With the relationship

the heat capacities of gases can be calculated in the temperature range 273 K - approx. 1300 K (0-1000 ° C). The unit [J / (mol K)] can easily be converted into the technical unit [J / (g K)] by dividing it by the molar mass [g / mol]. The Cp-Values ​​for 25 ° C were calculated as examples. (Note: a measurable gaseous phase also exists above the liquid phase of a substance).

Temperature dependence of Cp with gases

material molar mass
in g / mol
a b c d C.p (25 ° C)
in J / (mol K)
C.p (25 ° C)
in J / (g K)
hydrogen 2,016 29,09 -0,8374 2,013 0,0000 29,0 14,4
oxygen 32,00 27,96 4,180 -0,1670 0,0000 29,2 0,912
nitrogen 28,01 28,30 2,537 0,5443 0,0000 29,1 1,04
Carbon monoxide 28,01 27,63 5,024 0,0000 0,0000 29,1 1,04
Carbon dioxide 44,01 21,57 63,74 -40,53 9,684 37,2 0,846
Water (gaseous) 18,02 30,38 9,621 1,185 0,000 33,4 1,85
methane 16,04 17,46 60,50 1,118 -7,210 35,4 2,21
Ethane 30,07 5,355 177,8 -68,75 8,520 52,5 1,75
n-propane 44,10 -5,062 308,7 -161,9 33,33 73,5 1,67
n-butane (gaseous) 58,12 -0,05024 387,3 -201,0 40,64 98,6 1,70
n-pentane (gaseous) 72,15 0,4145 480,6 -255,2 52,85 122 1,70
n-hexane (gaseous) 86,18 1,792 570,9 -306,2 64,04 147 1,70

literature

  • Gustav Kortüm: Introduction to chemical thermodynamics. Verlag Chemie, Basel 1981, ISBN 3-527-25881-7 (or Vandenhoeck & Ruprecht, Göttingen 1981, ISBN 3-525-42310-1)
  • Walter J. Moore, Dieter O. Hummel: Physical chemistry. Verlag de Gruyter, Berlin / New York 1986, ISBN 3-11-010979-4
  • Handbook of Chemistry and Physics, 59th edit. Pages D-210, D-211.

Categories: Thermodynamics | List (chemistry) | Substance property