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MHT CET202019 Oct 2020Evening ShiftChemistryThermodynamics (C)Actual

When 6 0 ~g of graphite reacts with dihydrogen to give methane gas, 37 4 ~kJ of heat is liberated. What is standard enthalpy of formation of CH _ 4_ (g) ?

Options

  1. A112 2 ~kJ ~mol 1
  2. B-74 8 ~kJ ~mol ⁻¹
  3. C-37 4 ~kJ ~mol ⁻¹
  4. D-112 2 ~kJ ~mol ⁻¹

Correct answer

B. -74 8 ~kJ ~mol ⁻¹

Step-by-step solution

(A) C _ (8) +2 H _ 2(8) CH _ 4( ~g ) For 6.0 ~g of graphite, H =-37.4 ~kJ For 12.0 ~g of graphite, H ⁰= -37.4 12 6 =-74.8 ~kJ ~mol ⁻¹

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