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AP EAMCET20225 Jul 2022Evening ShiftChemistryThermodynamics (C)Actual

For a reaction 2 CO ( g )+ O ₂( ~g ) 2 CO ₂( ~g ) , _ r G ^0=-128 ~kJ at 300 ~K . If _ r S ^0 of the reaction is -40 ~J ~K ⁻¹ , calculate _ r U of the reaction.

Options

  1. A-137.5 ~kJ
  2. B-128 ~kJ
  3. C-140 ~kJ
  4. D126.2 ~kJ

Correct answer

A. -137.5 ~kJ

Step-by-step solution

_ r G ^ = _ r H ^ - T _ r S ^ or -128= _ r H ^ + (300 40 10⁻³ ) or _ r H ^ =-140 ~kJ or _ r U ^ + nRT =-140 or _ r U ^ =-140+ (8.314 10⁻³ 300 ) [ n =-1] or _ r U ^ =-140+2.5=-137.5 ~kJ

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