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KCET2010ChemistryThermodynamics (C)

For the reversible reaction. A ( s )+ B ( g ) C ( g )+ D ( g ); G ^ =-350 ~kJ Which one of the following statements is true?

Options

  1. AThe entropy change is negative
  2. BEquilibrium constant is greater than one
  3. CThe reaction should be instantaneous
  4. DThe reaction is thermodynamically not feasible

Correct answer

B. Equilibrium constant is greater than one

Step-by-step solution

In the reversible reaction, aligned A ( s )+ B ( g ) C ( g )+ D ( g ) G ^ =-350 ~kJ aligned Since, the randomness increases (because solid is changing into gas), entropy will increase and thus, S is positive. Reversible reaction never undergo to completion (ie, never be instantaneous). For the given reaction, G ^ =-350 ~kJ and we know that aligned G^ &=-R T K -350 &=-R T K aligned ie, K (equilibrium constant) is greater than one. Moreover, the reaction is thermodynamically feasible.

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