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KCET2026ChemistryThermodynamics (C)

A: Entropy of a perfect crystalline solid at absolute zero approaches zero. B: For spontaneity of a reaction, T S > H . Among the two statements given above, identify the correct answer from the options given below.

Options

  1. ABoth ' A ' and ' B ' are true
  2. B'A' is true but 'B' is false
  3. CBoth 'A' and 'B' are false
  4. D' A ' is false but ' B ' is true

Correct answer

A. Both ' A ' and ' B ' are true

Step-by-step solution

Statement A is based on the third law of thermodynamics, which states that the entropy of a perfectly crystalline solid approaches zero as the temperature approaches absolute zero. Thus, Statement A is true. For a reaction to be spontaneous at constant temperature and pressure, the change in Gibbs free energy ( G ) must be negative ( G From the Gibbs-Helmholtz equation: G = H - T S For spontaneity, G H - T S T S > H Thus, Statement B is also true. Both Statement A and Statement B are true. Answer: Both ' A ' and '

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