Search results
Results From The WOW.Com Content Network
The specific heat capacities of iron, granite, and hydrogen gas are about 449 J⋅kg −1 ⋅K −1, 790 J⋅kg −1 ⋅K −1, and 14300 J⋅kg −1 ⋅K −1, respectively. [4] While the substance is undergoing a phase transition , such as melting or boiling, its specific heat capacity is technically undefined, because the heat goes into ...
The specific heat of the human body calculated from the measured values of individual tissues is 2.98 kJ · kg−1 · °C−1. This is 17% lower than the earlier wider used one based on non measured values of 3.47 kJ · kg−1· °C−1.
All values refer to 25 °C and to the thermodynamically stable standard state at that temperature unless noted. Values from CRC refer to "100 kPa (1 bar or 0.987 standard atmospheres)". Lange indirectly defines the values to be standard atmosphere of "1 atm (101325 Pa)", although citing the same NBS and JANAF sources among others.
In monatomic gases (like argon) at room temperature and constant volume, volumetric heat capacities are all very close to 0.5 kJ⋅K −1 ⋅m −3, which is the same as the theoretical value of 3 / 2 RT per kelvin per mole of gas molecules (where R is the gas constant and T is temperature). As noted, the much lower values for gas heat ...
For hydrogen, the difference is much more significant as it includes the sensible heat of water vapor between 150 °C and 100 °C, the latent heat of condensation at 100 °C, and the sensible heat of the condensed water between 100 °C and 25 °C. In all, the higher heating value of hydrogen is 18.2% above its lower heating value (142 MJ/kg vs ...
1.80 [16] 1.26: battery, Fluoride-ion [citation needed] 1.7: 2.8: battery, Hydrogen closed cycle H fuel cell [17] 1.62: Hydrazine decomposition (as monopropellant) 1.6: 1.6: Ammonium nitrate decomposition (as monopropellant) 1.4: 2.5: Thermal Energy Capacity of Molten Salt: 1 [citation needed] 98% [18] Molecular spring approximate [citation ...
The gas constant R is defined as the Avogadro constant N A multiplied by the Boltzmann constant k (or k B): = = 6.022 140 76 × 10 23 mol −1 × 1.380 649 × 10 −23 J⋅K −1 = 8.314 462 618 153 24 J⋅K −1 ⋅mol −1. Since the 2019 revision of the SI, both N A and k are defined with exact numerical values when expressed in SI units. [2]
For example, the atomic mass constant is exactly known when expressed using the dalton (its value is exactly 1 Da), but the kilogram is not exactly known when using these units, the opposite of when expressing the same quantities using the kilogram.