Explore BrainMass

Explore BrainMass


    Enthalpy is a measure of the total energy of a thermodynamic system. It includes the internal energy, the amount of energy required to create a system, and the amount of energy required to make room for it by displacing its environment and stabling its volume and pressure.

    Enthalpy is a thermodynamic potential. It is a state function and an extensive quantity. It is a state function and extensive quantity. The unit of measurement for enthalpy is joule J. Enthalpy is the preferred expression of system energy changes in many chemical, biological, and physical measurements because it simplifies certain descriptions of energy transfer. Enthalpy change accounts for energy transferred to the environment at constant pressure through expansion or heating.

    The enthalpy of a homogeneous system is defined as

    H = U + pV


    H is the enthalpy of the system

    U is the internal energy of the system

    p is the pressure of the system

    V is the volume of the system

    Enthalpy is an extensive property. This means that for homogeneous systems, the enthalpy is proportional to the size of the system.

    For inhomogeneous systems the enthalpy is the sum of the enthalpies of the composing subsystems

    H = ∑kHk

    Where the label k refers to the various subsystems

    © BrainMass Inc. brainmass.com May 28, 2024, 10:59 am ad1c9bdddf

    BrainMass Solutions Available for Instant Download

    The change in specific enthalpy the steam(Gas) turbine

    A steam turbine takes in steam at the rate of 6000 kg hour^-1 and its power output is 800 kW. Neglect any heat loss from the turbine. Find the change in the specific enthalpy of the steam as it passes through the turbine if (a) the entrance and exit are at the same elevation and the entrance and exit velocities are negligible (b

    Heat: Specific Heat (Method of Mixtures)

    Water in an open metal drum is to be heated from room temperature (25 degree C) to 80 degree C by adding steam slowly enough that all the steam condenses. The drum initially contains 100 kg of water, and steam is supplied at 3.0 bar and 300C. How many kilograms of steam should be added so that the final temperature of the wate


    Suppose you add 113.1 grams of ice to 200.1 grams of water in an insulated cup, where the water is initially at 34.9 oC. How many grams of ice remain after the system reaches thermal equilibrium? The heat capacity of water is 4.184 J/goC and the enthalpy of melting ice is 334 J/g. If all the ice is melted, just enter 0.00

    What diameters of inlet and outlet pipes is required?

    Steam flows into a reducing valve with a pressure of 1400kpa+ dryness fraction ).98. It leaves the valve with a pressure of 150kpa. What diameters of inlet and outlet pipes would be required for a flow of 2270kg per hour with a velocity of 15m/s both before and after the reducing valve? Assume no losses+ enthalpy per kg steam b