Definitions for

**"Enthalpy"****Related Terms:**Heat capacity, Specific heat, Specific heat capacity, Heat content, Btu, British thermal unit, Kilocalorie, Heat, Calorie, Thermal efficiency, Cop , B.t.u, Hspf, Gibbs free energy, Second law of thermodynamics, Seer , Temperature, Thermal conductivity, Total heat, Thermal energy, Calorimetry, Heat flow, Latent heat of vaporization, Heating value, Coefficient of performance, Calorific value, Eer, Absolute zero, Entropy, Btuh, Sensible heat, Internal energy, Heat load, Latent heat, Heat transfer coefficient, Thermodynamics, Heat energy, Calorimeter, Heat of vaporization, Heating seasonal performance factor, Solar heating, Energy efficiency ratio, Heat rate, Seasonal energy efficiency ratio, Rankine cycle, Thermal coefficient of expansion, Thermal conductance, Geothermal, Cte, Therm

the thermodynamic quantity measuring the heat of a substance.

The quantity of heat necessary to raise the temperature of a substance from one point to a higher temperature. The quantity of heat includes both latent and sensible.

Heat; in a chemical reaction, the enthalpy of the reactants or products is equal to their total bond energies.

(Heat Content) is the sum of the internal and external energies.

The term given to total energy.

A thermodynamic property of a system given the symbol H and defined as H = U + pV (U the internal energy, p the pressure and V the volume). It is a state function. It is a State Function

Thermodynamic property of a working substance defined as H = U+PV, where = internal energy, = pressure and = volume of system. Useful in studying flow process, replacing total heat.

(H) is the heat content of unit mass of the atmosphere, in kJ/kg, relative to the heat content of 0 deg ?C dry air. It is indicated on the psychrometric chart by a third set of sloping lines, near to, but not quite the same as the web-bulb lines. In order to avoid confusion, there are no lines shown, but external scales are given on two sides.

Entrainment ratios Entropy

that part of the energy of a substance which is due to the motion of its particles; the heat content of a system at constant pressure. (see change in enthalpy, Î”H)

Heat flow at constant pressure. Because chemists most often conduct reactions at a constant pressure of 1 atm, enthalpy and heat of reaction are usually synonymous.

The sum of the internal energy plus the product of the pressure times the volume of the gas in a system: H = E + PV.

The total quantity of heat energy contained in a substance, also called total heat; the thermodynamic property of a substance defined as the sum of its internal energy plus the quantity Pv/J, where P = pressure of the substance, v = its volume, and J = the mechanical equivalent of heat.

H (from the Greek word enthalpien, which means to heat) is a property and is defined as the sum of the internal energy U and the PV product.

(thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure; "enthalpy is the amount of energy in a system capable of doing mechanical work"

function defined by the sum of internal energy of a system and product of its pressure by its volume

A measure of the quantity of internal energy (or heat) that is in a given amount of material.

The total energy content of a system, regardless of energy quality.

The amount of heat a substance contains determined from a predetermined base or point.

The heat content of a specific amount of substance.

A state function where it is the heat supplied to a system at constant pressure to the system.

A thermodynamic property of a substance, defined as the sum of its internal energy plus the pressure of the substance times its volume, divided by the mechanical equivalent of heat. The total heat content of air; the sum of the enthalpies of dry air and water vapor, per unit weight of dry air; measured in Btu per pound (or calories per kilogram).

A thermodynamic function of a system, equivalent to the internal energy plus the product of the pressure and the volume.

Heat content or total heat, including both sensible and latent heat. The amount of heat contained in a refrigerant at any given temperature with reference to -40°F.

Is the sum of the internal and external energies.( 030)

Total heat content, expressed in BTU per pound, above an arbitrary set of conditions chosen as the base or zero point.

the enthalpy H of a physical systems consists of the inner energy U of the system and the volume work pV: H = U + pV

Change in heat.

a thermodynamic quantity equal to the internal energy of a system plus the product of the pressure and volume. It is equal to the heat change in constant-pressure reactions (most biological reactions).

A thermodynamic property of a fluid. The enthalpy of a fluid consists of the energy associated with the fluid at a microscopic level (related to the temperature of the fluid) plus the energy present in the form of pressure at the inlet and outlet of the system.

The sum of the internal energy of a body and the product of its volume multiplied by the pressure.

Total amount of heat in one pound of a substance.Entropy - Mathematical factor used in engineering calculations. Energy in a system.

a thermodynamic state function, generally measured in kilojoules per mole. In chemical reactions the enthalpy change (deltaH) is related to changes in the free energy (deltaG) and entropy (deltaS) by the equation: deltaG = deltaH - T.deltaS

The amount of energy in joules required to heat 1 gram of fabric from a temperature of 20°C to its melting point.

Internal energy of a working fluid, usually stated in BTU/lbs.

A thermal property of a fluid which is a function of state and is defined as the sum of stored mechanical potential energy and internal energy. It is generally expressed in Btu per pound of fluid (joules per kilogram).

The heat content per unit mass of a substance.

In thermodynamics and molecular chemistry, the enthalpy or heat content (denoted as H or ΔH, or rarely as Ï‡) is a quotient or description of thermodynamic potential of a system, which can be used to calculate the "useful" work obtainable from a closed thermodynamic system under constant conditions.