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Thermodynamics

Question
CBSEENCH11008298

If the enthalpy change for the transition of liquid water to steam is 30kJ mol-1 at 27oC, the entropy change for the process would be. 

  • 1.0 J mol- K-1

  • 0.1 J mol-1 K-1

  • 100 J  mol-1 K-1

  • 10 J mol-1 K-1

Solution

C.

100 J  mol-1 K-1

increment straight G to the power of straight o space equals space increment straight H to the power of straight o space minus space straight T increment straight S to the power of straight o

Given comma space increment straight H subscript vap space equals space 30 space kJ space mol to the power of negative 1 end exponent

increment straight G to the power of straight o space equals space 0 space at space equilibrium comma

increment straight S subscript vap space equals space fraction numerator increment straight H subscript vap over denominator straight T end fraction

space equals space fraction numerator 30 space straight x space 10 cubed space straight x space straight J space mol to the power of negative 1 end exponent over denominator 300 space straight K end fraction
space equals space 100 space straight J space mol to the power of negative 1 end exponent space straight K to the power of negative 1 end exponent