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MHT CET2018ChemistryThermodynamics (C)

Calculate the work done during combustion of 0.138 k g of ethanol, ( C 2 H 5 O H ( l ) ) at at 300 K. Given: R = 8.314 J k - 1 m o l - 1 and molar mass of ethanol = 46 g m o l - 1 .

Options

  1. A- 7482 J
  2. B7482 J
  3. C- 2494 J
  4. D2494 J

Correct answer

B. 7482 J

Step-by-step solution

Stoichiometry coefficients are Weight of ethanol 0.138 kg = 138 gm , moles of ethanol 1 3 8 / 4 6 = 3 mole 3 C 2 H 5 OH l + 9 O 2 g → 6 CO 2 g + 9 H 2 O l Δ n g = 6 - 9 = - 3 Work = - Δ n g R T = - - 3 × 8.314 × 3 0 0 = 7 4 8 2 J

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