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MHT CET202616 April 2026Morning ShiftChemistryThermodynamics (C)Actual

In a particular reaction, 4 kJ heat is released by the system and 12 kJ work done on the system. Calculate the H and U .

Options

  1. AH = 4 kJ and U = 16 kJ
  2. BH = -4 kJ and U = 8 kJ
  3. CH = -4 kJ and U = -16 kJ
  4. DH = 4 kJ and U = -16 kJ

Correct answer

B. H = -4 kJ and U = 8 kJ

Step-by-step solution

Heat released by the system, q = -4 kJ. Work done on the system, w = +12 kJ. According to the first law of thermodynamics: U = q + w U = -4 + 12 = 8 kJ. For a reaction at constant pressure, the enthalpy change is equal to the heat exchanged: H = q_p = -4 kJ. Answer: H = -4 kJ and U = 8 kJ

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