Specific heat of substances

Assuming no chemical reaction, what will happen if we place a piece of metal at one temperature into water at another temperature The metal will gain energy from or lose energy to the water until their temperatures are the same. Whichever was at the higher temperature initially will lose energy to the other. In the absence of any energy loss to any other body, the quantity of heat removed from one will be added to the other. We can use this fact to measure specific heats of substances, or to predict the final temperatures to which such combinations will arrive. The principle involved may be summarized in the equation ... 

A sample of substance X has a mass of 123 g. When the sample releases 795 J of heat, its temperature falls from 45.1°C to 17.6°C. What is the specific heat of substance X ... 

The most obvious test of the validity of the equipartition principle is the attempt to calculate the energy content and thus the specific heat of substances composed of molecules simple enough for a fair guess at their structure and mechanics to be made. 

Heat lost or gained by a system can be calculated by heat = (mass of substance)(specific heat of substance)( At). 

Domb 0 and Sykes M F 1957 Specific heat of a ferromagnetic Substance above the Ourie point Phys. Rev. 129 567... 

The specific heat of a substance is the ratio of the heat required to raise the temperature of a certain weight by I C to that required to raise the temperature of the same weight of water by l°C. 

The heat capacity of a subshince is defined as the quantity of heat required to raise tlie temperature of tliat substance by 1° the specific heat capacity is the heat capacity on a unit mass basis. The term specific heat is frequently used in place of specific heat capacity. This is not strictly correct because traditionally, specific heal luis been defined as tlie ratio of the heat capacity of a substance to the heat capacity of water. However, since the specific heat of water is approxinuitely 1 cal/g-°C or 1 Btiiyib-°F, the term specific heal luis come to imply heat capacity per unit mass. For gases, tlie addition of heat to cause tlie 1° tempcniture rise m iy be accomplished either at constant pressure or at constant volume. Since the mnounts of heat necessary are different for tlie two cases, subscripts are used to identify which heat capacity is being used - Cp for constant pressure or Cv for constant volume. Tliis distinction does not have to be made for liquids and solids since tliere is little difference between tlie two. Values of heat capacity arc available in the literature. ... 

The specific heat of a substance must always be defined relatively to a particular set of conditions under which heat is imparted, and it is here that the fluid analogy is very liable to lead to error. The number of heat units required to produce unit rise of temperature in a body depends in fact on the manner in which the heat is communicated. In particular, it is different according as the volume or the pressure is kept constant during the rise of temperature, and we have to distinguish between specific heats (and also heat capacities) at constant volume and those at constant pressure, as well as other kinds to be considered later. 

The specific heats of diamond and graphite are reduced to 19 and Tx() respectively between the ordinary temperature and the boiling-point of liquid hydrogen the specific heats of the substances between the temperatures of liquid air and liquid hydrogen are in fact less than those of any other substances, even less than that of a gas at constant volume. 

Clausius (1850), in considering Regnault s data for the latent heat of steam, introduced a new specific heat, applicable to either phase of a saturated complex of two phases, viz., the amount of heat absorbed in raising the temperature of unit mass of a saturated phase by 1°, the pressure being at the same time varied so as to preserve the substance in a saturated state. In the case of a vapour, this is called the specific heat of saturated vapour (a). 

The specific heats of the various substances, to calculate the value of (Tr — T) required in the application of KirchhofTs equation, and the evaluation of the integral for hiK ... 

The quantity of heat (J/kg/K) required to raise the temperature of unit mass of the substance through 1 °C. The specific heat of rubber (around 2000) is much higher than that of metals (around 400 for steel) and it is therefore much more expensive to heat rubber than the mould, mandrel or last on which it is cured. 

The equilibrium state is generated by minimizing the Gibbs free energy of the system at a given temperature and pressure. In [57], the method is described as the modified equilibrium constant approach. The reaction products are obtained from a data base that contains information on the enthalpy of formation, the heat capacity, the specific enthalpy, the specific entropy, and the specific volume of substances. The desired gaseous equation of state can be chosen. The conditions of the decomposition reaction are chosen by defining the value of a pair of variables (e.g., p and T, V and T). The requirements for input are ... 

The coffee-cup calorimeter can be used to measure the heat changes in reactions that are open to the atmosphere, qp, constant pressure reactions. We use this type of calorimeter to measure the specific heats of solids. We heat a known mass of a substance to a certain temperature and then add it to the calorimeter containing a known mass of water at a known temperature. The final temperature is then measured. We know that the heat lost by the added substance (the system) is equal to the heat gained by the surroundings (the water and calorimeter, although for simple coffee-cup calorimetry the heat gained by the calorimeter is small and often ignored) ... 

Specific heat is the amount of heat required to raise the temperature of one gram of a substance by 1°C. The specific heat of water is 1 calorie or 4.184 Joule. 

Scottish chemist, physicist, and physician. Professor of chemistry at Glasgow. He clearly characterized carbon dioxide ( fixed air ) as the gas which makes caustic alkalies mild, and distinguished between magnesia and lime. He discovered the latent heats of fusion and vaporization, measured the specific heats of many substances, and invented an ice calorimeter. 

Specific heat of fusion. Defined as the quantity of heat in joules required to transform 1 kg of a substance at fusion temperature from the solid to the liquid state. 

The relationship between heat, specific heat, and temperature change is given by the equation Q = mcAT. In this equation, Q is the amount of heat absorbed or released in joules, m is the mass in grams, c is the specific heat of the substance, and AT is the... 

The specific heat of a substance is the amount of heat energy, in kJ, required to increase the temperature of 1 kg of the substance by 1 K. The specific heat of skim milk increases from 3.906 to 3.993 kJ kg-1 K-1 from 1 to 50°C. Values of 4.052 and 3.931 kJ kg-1 K-1 have been reported for skim and whole milks, respectively, at 80°C (Sherbon, 1988). The specific heat of milk is inversely related to its total solids content, although discontinuities have been observed around 70-80°C. Skim-milk powder usually has a specific heat in the range 1.172-1.340kJ kg-1 K-1 at 18-30°C. 

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