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AP EAMCET201822 Apr 2018Morning ShiftChemistryThermodynamics (C)Actual

From the following data aligned & CH ₃ OH (l)+ 3 2 O ₂(g) CO ₂(g)+2 H ₂ O (l) & _r H^ =-726 ~kJ ~mol ⁻¹ & H ₂(g)+ 1 2 O ₂(g) H ₂ O (l) ; & _r H ^ =-286 ~kJ ~mol ⁻¹ & C ( graphite )+ O ₂( ~g ) CO ₂( ~g ) ; & _r H ^ =-393 ~kJ ~mol ⁻¹ & aligned The standard enthalpy of formation of CH ₃ OH (l) in kJ mol ⁻¹ is

Options

  1. A-239
  2. B239
  3. C547
  4. D-905

Correct answer

A. -239

Step-by-step solution

aligned & From Eq. (ii) + (iii) - Eq. (i) & aligned -286 2-393-(-726)=7 & =-572-393+726 & =-965+726 & =-239 ~kJ / mol aligned aligned

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