The following constant-pressure molar quantities are available for water at 1 atm

CHEMISTRY · Multi-part · A Level · Chemistry · Thermodynamics · Thermodynamics

Problem

The following constant-pressure molar quantities are available for water at 1 atm. Heat capacity of ice (solid) Cs=37.6 J mol−1 K−1C_{\text{s}} = 37.6\,\text{J mol}^{-1}\,\text{K}^{-1} Heat capacity of liquid Cℓ=75.3 J mol−1 K−1C_{\ell} = 75.3\,\text{J mol}^{-1}\,\text{K}^{-1} Heat capacity of steam Cg=33.6 J mol−1 K−1C_{\text{g}} = 33.6\,\text{J mol}^{-1}\,\text{K}^{-1} Enthalpy of fusion at 0 ∘C0\,^{\circ}\text{C} ΔHfus=6.01 kJ mol−1\Delta H_{\text{fus}} = 6.01\,\text{kJ mol}^{-1} Enthalpy of vaporization at 100 ∘C100\,^{\circ}\text{C} ΔHvap=40.7 kJ mol−1\Delta H_{\text{vap}} = 40.7\,\text{kJ mol}^{-1} A student wishes to determine the molar entropy change when 2.00 mol of ice at −10.0 ∘C-10.0\,^{\circ}\text{C} is converted to steam at 110.0 ∘C110.0\,^{\circ}\text{C} at 1 atm. (a) Calculate the entropy change for warming the ice from −10.0 ∘C-10.0\,^{\circ}\text{C} to 0.0 ∘C0.0\,^{\circ}\text{C}. (b) Calculate the entropy change for melting the ice at 0.0 ∘C0.0\,^{\circ}\text{C}. (c) Calculate the entropy change for warming the liquid water from 0.0 ∘C0.0\,^{\circ}\text{C} to 100.0 ∘C100.0\,^{\circ}\text{C}. (d) Calculate the entropy change for vaporizing the liquid at 100.0 ∘C100.0\,^{\circ}\text{C}. (e) Calculate the entropy change for warming the steam from 100.0 ∘C100.0\,^{\circ}\text{C} to 110.0 ∘C110.0\,^{\circ}\text{C}. (f) Determine the total molar entropy change for the complete process and identify which single step contributes the largest fraction of the total. Support your conclusion with quantitative evidence.

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