The constant-pressure heat capacity of iron around its melting point of 1809 K is 46.02 J...

 

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The constant-pressure heat capacity of iron around its melting point of 1809 K is 46.02 J mol- K- for Fe(/) and 39.04 J mol- K- for Fe(s) in its face-centred cubic (fcc) allotrope. The standard enthalpy of fusion for Fe is 12.40 kJ mol-. Assume the heat capacity values are constant. (a) (i) Define entropy in a complete sentence. (ii) State the second law of thermodynamics as a complete sentence. (iii) State the second law of thermodynamics as an equation or inequality. (b) Calculate the entropy change of a system containing exactly 1 mol Fe cooled from a liquid at 1875 K to an fcc solid at 1795 K. The cooling and freezing process happens at 1 bar pressure. Present your answer with the correct units. (c) Calculate the standard entropy change of the surroundings for the process described in (b). The surroundings are at constant 1685 K. Present your answer with the correct units. (d) Calculate the standard entropy change of the universe for the process in (b). Present your answer with the correct units. (e) Explain why the answer in (d) is consistent with the freezing process being spontaneous. The constant-pressure heat capacity of iron around its melting point of 1809 K is 46.02 J mol- K- for Fe(/) and 39.04 J mol- K- for Fe(s) in its face-centred cubic (fcc) allotrope. The standard enthalpy of fusion for Fe is 12.40 kJ mol-. Assume the heat capacity values are constant. (a) (i) Define entropy in a complete sentence. (ii) State the second law of thermodynamics as a complete sentence. (iii) State the second law of thermodynamics as an equation or inequality. (b) Calculate the entropy change of a system containing exactly 1 mol Fe cooled from a liquid at 1875 K to an fcc solid at 1795 K. The cooling and freezing process happens at 1 bar pressure. Present your answer with the correct units. (c) Calculate the standard entropy change of the surroundings for the process described in (b). The surroundings are at constant 1685 K. Present your answer with the correct units. (d) Calculate the standard entropy change of the universe for the process in (b). Present your answer with the correct units. (e) Explain why the answer in (d) is consistent with the freezing process being spontaneous.

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Answers a i Entropy is a thermodynamic property that represents the degree of disorder or randomness within a system ii The second law of thermodynami... View the full answer