Mole-specific heat capacity

Consider an adiabatic tubular reactor (Davis, 1984)[15] with the following data length L = 2 m, radius Rp = 0.1 m, inlet reactant concentration cO = 30 moles/m3, inlet temperature TO = 700K, enthalpy AH = -10000 J/mole, specific heat capacity Cp = 1000 J/kg/K, activation energy Ea = 100 J/mole, p = 1200 kg/m3, velocity uO = 3 m/s, and rate constant kO = 5 s-1. Dimensionless concentration (y) and dimensionless temperature (9) are governed by material and energy balances as ... 

Specify what physical quantity should be multiplied by the mass-specific heat capacity to convert it into a mole-specific heat capacity ... 

Generally, in thermodynamic calculations the mole-specific heat capacity is used, defined by... 

The mole-specific heat capacity c of a substance is defined as the ratio between added heat 6Q per mole of substance and the temperature increment dT... 

Mole-specific heat capacity at constant volume is denoted c and mole-specific heat capacity at constant pressure is denoted Cp. Often, in technical calculations the so-called mass-specific heat capacity is used, defined by... 

Given the mole-specific heat capacity c of a substance (J/molK) how is this value converted into a mass-specific heat capacity c (J/kg K) ... 

A system consists of 5.00 kg of water in temperatnre equilibrium at 25.0 °C. A heat quantity of Q = 14630 J at constant pressure is added to the system from its surroundings so that the water temperature is increased to 25.7°C. Calculate the heat capacity of the system Cp (J/K), the mole-specific heat capacity of the water Cp (J/molK) and the mass-specific heat capacity Cp (J/kgK) of the water. The molar mass of H2O is 18.02 g/mol. 

I The mole-specific heat capacity cy for an ideal gas, cy = 12.5 J/molK, has been determined by measurement in a volume-constant calorimeter. Calculate the mole-specific heat capacity Cp (J/molK) of the gas ... 

T3 Because of the low coefficient of thermal expansion of sohd substances, the volume work SW = —pdV during heating of a sohd substance is negligible compared to the heat SQ = cdT. Mole-specific heat capacity (J/molK) divided by molar mass... 

Figure 5.1 is a graph of the specific heat capacity cp (heat capacity per gram) of aqueous sulfuric acid solutions at T — 298.15 K against A, the ratio of moles of water to moles of sulfuric acid. The values plotted were obtained from a very... 

Heat capacity is an extensive property the larger the sample, the more heat is required to raise its temperature by a given amount and so the greater is its heat capacity (Fig. 6.10). It is therefore common to report either the specific heat capacity (often called just specific heat ), Cs, which is the heat capacity divided by the mass of the sample (Cs = dm), or the molar heat capacity, Cm, the heat capacity divided by the amount (in moles) of the sample (Cm = C/n). For example, the specific heat capacity of liquid water at room temperature is 4.18 J-(°C) -g, or 4.18 J-K 1-g and its molar heat capacity is 75 J-K -mol1. 

Which of the equations given for AH is used here Both. You can see from the factor-label method solution that the atomic weight divided into the molar heat capacity is the specific heat capacity while the mass divided by atomic weight is the number of moles. Thus, we have cither moles times molar heat capacity times change in temperature or mass times specific heat times change in temperature. 

The specific heat capacity is the amount of heat needed to change the temperature of 1 gram of a substance by 1 K, while the molar heat capacity is the heat capacity per mole. 

If a substance is heated without a change of state, the amount of heat required to change the temperature of 1 gram by 1° C is called the specific heat capacity of the substance. Similarly, the molar heat capacity is the amount of heat needed to raise the temperature of 1 mole of a substance by 1° C. Table 7-2 shows the heat capacities of several elements and compounds. 

The heat capacity of a body is the amount of heat required to raise the temperature of that body 1K (1°C). For pure substances, it is most convenient to refer to quantities of molar heat capacity (heat capacity per mole) and, as discussed above, the specific heat capacity or, more commonly, the specific heat (heat capacity per unit of mass). As an example, the average specific heat of water is... 

Two solutions, initially at 25.08°C, were mixed in an insulated bottle. One consisted of 400mL of a weak monoprotic acid solution of concentration 0.200 mL. The other consisted of lOOmL of a 0.800mol of NaOH per liter of solution. The temperature rose to 26.25°C. How much heat is evolved in the neutralization of one mole of the acid Assume that the densities of all solutions are 1.00 g/cm3 and that their specific heat capacities are all 4.2 J/g K. Actually, these assumptions are in error by several percent, but they nearly cancel each other. 

Thermochemical measurements are based on the relationships between heat and temperature. The measurement that relates to the two is heat capacity, defined as the amount of heat that is required to raise the temperature of a substance 1°C. (The amount of substance is sometimes expressed in moles or in grams.) The heat capacity of a mole of a substance is known as the molar heat capacity, while the heat capacity for gram values of a substance are known as specific heat capacities. The specific heat of a substance is the amount of heat required to raise 1 gram of the substance 1°C. The formula that is used to calculate specific heat is Equation 17.4 ... 

The following symbols are used in the definitions of the dimensionless quantities mass (m), time (t), volume (V area (A density (p), speed (u), length (/), viscosity (rj), pressure (p), acceleration of free fall (p), cubic expansion coefficient (a), temperature (T surface tension (y), speed of sound (c), mean free path (X), frequency (/), thermal diffusivity (a), coefficient of heat transfer (/i), thermal conductivity (/c), specific heat capacity at constant pressure (cp), diffusion coefficient (D), mole fraction (x), mass transfer coefficient (fcd), permeability (p), electric conductivity (k and magnetic flux density ( B) ... 

When 1.00 L of 1.00 M Ba(N03)2 at 25.0°C is mixed with 1.00 L of 1.00 M Na2S04 at 25°C in a calorimeter, the white solid BaS04 forms and the temperature of the mixture increases to 28.1°C. Assuming that the calorimeter absorbs only a negligible quantity of heat, that the specific heat capacity of the solution is 4.18 J °C-1 g-1, and that the density of the final solution is 1.0 g/mL, calculate the enthalpy change per mole of BaS04 formed. 

Heat capacity Cp is defined as the energy required to change the temperature of a unit mass (specific heat) or mole (molar heat capacity) of the material by one degree. Typical units are J/(kg K). 

It s the molar Gibb s free energy and it s intensive. Conceptually, chemical potential is to Gibb s free energy what specific heat capacity is to heat capacity in the former it s per mole and the latter is typically per mass unit. 

RATIO OF SPECIFIC HEAT CAPACITIES, k MOLECULAR WEIGHT OF GAS, Ib/lb-mole AVERAGE COMPRESSIBILITY FACTOR, Z POLYTROPIC EFFICIENCY ... 

Heat capacity can be expressed in joules or calories per mole per degree (molar heat capacity), or in joules or calories per gram per degree the latter is called the specific heat capacity or just the specific heat. 

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