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MHT CET202525 Apr 2025Morning ShiftChemistryThermodynamics (C)Actual

Calculate H ^ for a reaction if S ^ =120 JK ⁻¹ and G ^ =28000 ~J

Options

  1. A15.94 kJ
  2. B31.83 kJ
  3. C94.12 kJ
  4. D63.76 kJ

Correct answer

D. 63.76 kJ

Step-by-step solution

The standard enthalpy change is determined using the Gibbs-Helmholtz equation: G^ = H^ - T S^ , with assumed standard temperature T = 298 ; K . Rewriting for H^ : H^ = G^ + T S^ Substituting G^ = 28000 ; J and S^ = 120 ; J K ⁻¹ : H^ = 28000 ; J + (298 ; K )(120 ; J K ⁻¹) = 63760 ; J Converting to kilojoules: 63760 ; J = 63.76 ; kJ . This value corresponds to option D .

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