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qid 11369 · engineering

Question: A closed system contains pure ammonia (NH_3) at an initial pressure and temperature of 1640psiaand 1460°R respectively. The ammonia then undergoes an isothermal expansion to a final pressure of 820psia. Using the generalized enthalpy correction chart calculate the change in specific enthalpy.

  1. 20.00 Btu/lbm
  2. 0.65 Btu/lbm
  3. 17.89 Btu/lbm
  4. 0.33 Btu/lbm
  5. 10.00 Btu/lbm
  6. 13.73 Btu/lbm
  7. 7.50 Btu/lbm
  8. -0.65 Btu/lbm
  9. 2.97 Btu/lbm
  10. 14.15 Btu/lbm

Our answer: F. 13.73 Btu/lbm Source quote machine-checked (exact quote)

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How it was answered

Multi-step solver (maze), replayed by code

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Current source

Wikipedia, "Departure function"

https://en.wikipedia.org/wiki/Departure_function

“In thermodynamics, a departure function is defined for any thermodynamic property as the difference between the property as computed for an ideal gas and the property of the species as it exists in the real world, for a specified temperature T and pressure P.”

Source quote machine-checked (exact quote)

retrieved 2026-09-18T00:34:13.335Z

page text sha256 d1aae20954a40c24… · content sha256 f1343e432f1790b4…

addendum maze_qid11369_b4_maze_input_ADDENDUM_source_rs20260918T003413Z · sha256 33af661d187d6192… · replaces the version below, addendum sha256 cd72226c934ced8b…

Earlier version (superseded)

No public source has been found for this card yet (3 places checked internally).

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