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A Question to Consider You have your freezer set at ‒15C. You open the freezer, grab some ice, and place it on your kitchen counter (your house thermostat is set at 25C). You get distracted and let the ice sit on the counter all day. What happens to the ice? How can you use thermodynamic principles to prove this will happen?  

A Question to Consider Calculate Suniv when you take 1 mole of ice at ‒15C. and let it sit in a room at 25C, 1 atm. Hfusion for ice is 6.02 kJ/mol at 0C, 1 atm Cp for water is 75.3 J/Kmol Cp for ice is 37.5 J/Kmol Assume Cp is constant over the temperature range in question.

A Question to Consider You have your freezer set at ‒15C. You open the freezer, grab some ice, and place it on your kitchen counter (your house thermostat is set at 0C). You get distracted and let the ice sit on the counter all day. What happens to the ice? How can you use thermodynamic principles to prove this will happen?  

A Question to Consider Calculate Suniv when you take 1 mole of ice at ‒15C. and let it sit in a room at 0C, 1 atm. Hfusion for ice is 6.02 kJ/mol at 0C, 1 atm Cp for water is 75.3 J/Kmol Cp for ice is 37.5 J/Kmol Assume Cp is constant over the temperature range in question.

Clicker Question Consider the spontaneous reaction: 2KClO3(s)  2KCl(s) + 3O2(g) Is the reaction endothermic or exothermic? a) Endothermic b) Exothermic c) More information is needed. d) I do not know how to answer this question.

Clicker Question A stable diatomic molecule spontaneously forms from its atoms at constant pressure and temperature. How does temperature affect the reaction? a) An increase in temperature makes the reaction more favorable. b) An increase in temperature makes the reaction less favorable. c) We cannot tell from the information given. d) I do not know.

Clicker Question Given the following enthalpies of formation, determine the enthalpy of vaporization of methanol (CH3OH): CH3OH(l)  CH3OH(g) ΔHf° (kJ/mol) –239 –201   a) 38 kJ/mol b) –38 kJ/mol c) 440 kJ/mol d) –440 kJ/mol e) I do not know.

Clicker Question Given the following absolute entropies, determine the value of ΔS° for methanol (CH3OH): CH3OH(l)  CH3OH(g) S° (J/Kmol) 127 240   a) –113 J/Kmol b) 113 J/Kmol c) –367 J/Kmol d) 367 J/Kmol e) I do not know.