Which from the following defines enthalpy of a system?
Which from the following defines enthalpy of a system?
Ratio of pressure to volume
Product of pressure and volume
Internal energy (U) + PV
Internal energy (U) - PV
Solution
- (1) Ratio of pressure to volume: This is incorrect. The ratio of pressure to volume is not related to enthalpy.
- (2) Product of pressure and volume: This is also incorrect. The product of $P$ and $V$ is part of the enthalpy formula but doesn't define it by itself.
- (3) Internal energy (U) + PV: This is the correct definition of enthalpy. Enthalpy is the sum of internal energy and $P \times V$.
- (4) Internal energy (U) - PV: This is incorrect. Enthalpy involves adding, not subtracting, PV from internal energy.