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How do you calculate the change in enthalpy?

Best Answer:

When you change the temperature of a system, the internal energy of the system also changes. The enthalpy of a system is the total energy of the system divided by the total mass of the system. The enthalpy of a system can be calculated using the following equation:

enthalpy = internal energy (J)

- heat released (Q)

In this equation, "Q" is the heat released and "J" is the internal energy. The heat released is simply the total heat supplied to the system minus the total heat used by the system. The internal energy of the system can be calculated using the following equation:

internal energy (J) = total energy (J)

+ work done (W)

The work done is simply the total power (J) used to change the temperature of the system. The equation can be simplified to the following equation:

enthalpy = internal energy (J)

- work done (W)

The change in enthalpy can be calculated using the following equation:

change in enthalpy = internal energy (J)

- work done (W)

The change in enthalpy is simply the difference between the internal energy of the system before the change in temperature and the internal energy of the system after the change in temperature.

Hess's Law Problems & Enthalpy Change - Chemistry

66 Votes


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