Sodium heat capacity

Brunauer and co-workers [129, 130] found values of of 1310, 1180, and 386 ergs/cm for CaO, Ca(OH)2 and tobermorite (a calcium silicate hydrate). Jura and Garland [131] reported a value of 1040 ergs/cm for magnesium oxide. Patterson and coworkers [132] used fractionated sodium chloride particles prepared by a volatilization method to find that the surface contribution to the low-temperature heat capacity varied approximately in proportion to the area determined by gas adsorption. Questions of equilibrium arise in these and adsorption studies on finely divided surfaces as discussed in Section X-3. 

Sodium Pentaborate Pentahydrate. Sodium pentaborate pentahydrate, NaB Og -5H20 or Na20 -5B203 -10H2O formula wt, 295.11 monoclinic sp gr, 1.713 exists in nature as the mineral sborgite [12272-01 -4]. Heat capacity, entropy, and other thermal measurements have been made at 15-345 K (85). 

Heat capacity data for metaborate solutions have been reported (87). The solubiUty of sodium metaborate tetrahydrate in methanol at 40°C is 26.4 wt % (61). 

Potassium Pentaborate Tetrahydrate. Potassium pentaborate tetrahydrate, KB Og 4H2O or K2O -5B202 8H20 formula wt, 293.20 orthorhombic prisms sp gr, 1.74 heat capacity, 329.0 J/(mol-K) [78.6 cal/(mol-K)] at 296.6 K is much less soluble than sodium pentaborate (Tables 9 and 10). Heat capacity measurements on the soHd have been made over a broad temperature range (85). 

The heat capacity of sodium cyanide has been measured between 100 and 345 K (48). To convert to cal, divide by 4.184. 

Figure 12.3 Density and specific heat capacity (a) Sodium chloride, (b) Calcium chloride...

Table 25. Enthalpy, H -H0, and heat capacity, Cp, of liquid sodium...

K. S. Pitzer and L. V. Coulter. "The Heat Capacities. Entropies and Heats of Solution of Anhydrous Sodium Sulfate and of Sodium Sulfate Decahydrate. The Application of the Third Law of Thermodynamics to Hydrated Crystals". J. Am. Chem. Soc.. 60. 1310-1313 (1938). 

G. Brodale and W. F. Giauque, "The Heat of Hydration of Sodium Sulfate. Low Temperature Heat Capacity and Entropy of Sodium Sulfate Decahydrate", J. Am. Chem. Soc., 80, 2042-2044 (1958). 

Special correlations have also been developed for liquid metals, used in recent years in the nuclear industry with the aim of reducing the volume of fluid in the heat transfer circuits. Such fluids have high thermal conductivities, though in terms of heat capacity per unit volume, liquid sodium, for example, which finds relatively widespread application, has a value of Cpp of only 1275 k.l/ni1 K. 

Here, Q is the heat energy input per area p and Cp are the density and specific heat capacity, respectively and indices g, d, and s refer to the gas, metal, and liquid sample layers, respectively. With Eq. (106), the thermal conductivity of the sample liquid is obtained from the measured temperature response of the metal without knowing the thermal conductivity of the metal disk and the thickness of the sample liquid. There is no constant characteristic of the apparatus used. Thus, absolute measurement of thermal conductivity is possible, and the thermal conductivities of molten sodium and potassium nitrates have been measured. ... 

What is the evaporation rate and yield of the sodium acetate hydrate CH3C00Na.3H20 from a continuous evaporative crystalliser operating at 1 kN/m2 when it is fed with 1 kg/s of a 50 per cent by mass aqueous solution of sodium acetate hydrate at 350 K The boiling point elevation of the solution is 10 degK and the heat of crystallisation is 150 kJ/kg. The mean heat capacity of the solution is 3.5 kJ/kg K and, at 1 kN/m2, water boils at 280 K at which temperature the latent heat of vaporisation is 2.482 MJ/kg. Over the range 270-305 K, the solubility of sodium acetate hydrate in water s at T(K) is given approximately by ... 

Silvester, L. F. Pitzer, K. S. "Thermodynamics of Electrolytes. 8. High-Temperature Properties, Including Enthalpy and Heat Capacity with Application to Sodium Chloride" J. Phys. Chem., 1977, 81, 1822. 

A solution containing 23 per cent by mass of sodium phosphate is cooled from 313 to 298 K in a Swenson-Walker crystalliser to form crystals of Na3P04.12H20. The solubility of Na3P04 at 298 K is 15.5 kg/100 kg water, and the required product rate of crystals is 0.063 kg/s. The mean heat capacity of the solution is 3.2 kJ/kg deg K and the heat of crystallisation is 146.5 kJ/kg. If cooling water enters and leaves at 288 and 293 K, respectively, and the overall coefficient of heat transfer is 140 W/m2 deg K, what length of crystalliser is required ... 

Figure 4.3. Molar heat capacities of solid sodium (o) and palladium ( ). [Data from G. L. Pickard and F. E. Simon, Proc. Phys. Soc. 61, 1 (1948).]...

Figure 8.27 Experimental values of standard partial molal heat capacity of sodium acetate (A) and ethylene (B) in water as a function of P(°C) at pressures corresponding to water-vapor equilibrium. Interpolating curves generated by the HKF model equations. Reprinted from E. L. Shock and H. C. Helgeson, Geochimica et Cosmochimica Acta, 54, 915-946, copyright 1990, with kind permission from Elsevier Science Ltd., The Boulevard, Langford Lane, Kidlington 0X5 1GB, UK.

Allred G. C. and Woolley E. M. (1981). Heat capacities of aqueous acetic acid, sodium acetate, ammonia, and ammonium chloride at 283.15 K, 298.15 K, and 313.15 K ACfp for ionization of acetic acid and for dissociation of ammonium ion. J. Soln. Chem., 14 549-560. 

Figure 1 Apparent molar volumes and heat capacities of sodium deca noate In water (ref. 11) and In 0.05 mol kg of 2-butoxy-ethanol at 25°C.

Figure 2 Volumes and heat capacities of transfer of 2-butoxyethanol from water to aqueous sodium decanoate at 25°C.

Figure 4 Heat capacities of transfer of sodium decanoate from water to 2-butoxyethanol solutions at 25°C. Simulations (curves A and B) with a chemical equilibrium model ...

The sp-valent metals such as sodium, magnesium and aluminium constitute the simplest form of condensed matter. They are archetypal of the textbook metallic bond in which the outer shell of electrons form a gas of free particles that are only very weakly perturbed by the underlying ionic lattice. The classical free-electron gas model of Drude accounted very well for the electrical and thermal conductivities of metals, linking their ratio in the very simple form of the Wiedemann-Franz law. However, we shall now see that a proper quantum mechanical treatment is required in order to explain not only the binding properties of a free-electron gas at zero temperature but also the observed linear temperature dependence of its heat capacity. According to classical mechanics the heat capacity should be temperature-independent, taking the constant value of kB per free particle. 

Sodium metal is sometimes used as a cooling agent in heat-exchange units because of its relatively high molar heat capacity of 28.2 J/(mol-°C). What is the specific heat of sodium in J/ (g °C) ... 

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