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MHT CET202019 Oct 2020Morning ShiftChemistryThermodynamics (C)Actual

Standard enthalpy of formation of water is -286 ~kJ ~mol ⁻¹ . When 1800 mg of water is formed from its constituent elements in their standard states the amount of energy liberated is

Options

  1. A2 86 ~kJ
  2. B5 72 ~kJ
  3. C57 2 ~kJ
  4. D28 6 ~kJ

Correct answer

D. 28 6 ~kJ

Step-by-step solution

(D) H _ 2( ~g ) + 1 2 O _ 2( ~g ) H ₂ O _ ( ) H _ f ⁰=-286 ~kJ ~mol ⁻¹ For 18 ~g of H ₂ O , amount of energy liberated =286 ~kJ ~mol ⁻¹ For 1.8 ~g of H ₂ O , amount of energy liberated = 1.8 286 18 =28.6 ~kJ

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