What This Document Is
This document is an answer key for Worksheet Seven in Coastal Carolina University’s General Chemistry I (CHEM 111) course, prepared by Professor Kuhler. It provides solutions to problems focused on calculating enthalpy, entropy, and Gibbs Free Energy for phase changes, specifically the transition of water between liquid and gaseous states. The worksheet also includes questions about the spontaneity of these phase changes at different temperatures.
Why This Document Matters
This answer key is intended for students enrolled in CHEM 111 who have completed Worksheet Seven. It serves as a self-assessment tool to verify understanding of thermodynamic principles applied to phase transitions. Students can use it to check their work, identify areas of confusion, and reinforce their grasp of key concepts before assessments. It’s particularly useful for understanding how to apply formulas and interpret results related to enthalpy, entropy, and spontaneity.
Common Limitations or Challenges
This document *only* provides the correct answers to the problems on Worksheet Seven. It does *not* offer detailed explanations of the underlying chemical principles or step-by-step solutions to the problems. Students still need a solid understanding of thermodynamics and the ability to apply the relevant equations independently. It also assumes students have access to the necessary thermodynamic tables (referenced as being at the end of the textbook) and the Excel sheet containing individual starting data for certain problems.
What This Document Provides
The full answer key includes:
* Calculated values for ΔH, ΔS, and ΔG for the phase change of water from liquid to gas at 25.0°C.
* Calculated values for ΔH, ΔS, and ΔG for the phase change of methanol from liquid to gas.
* Determinations of spontaneity at specific temperatures (-95.0°C and 495.0°C) for the methanol phase change.
* The temperature at which the methanol phase change becomes spontaneous.
* Answers to questions regarding the expected boiling point and potential sources of error in calculations.
* A point breakdown for the worksheet.
This preview does *not* include the full worked solutions or explanations for *how* these answers were obtained. It does not include the individual starting data provided to students on the Excel sheet.