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Catalyst

Catalyst. Define endothermic. Give an example. Define exothermic. Give an example I cool a glass of water, is this an endothermic process or an exothermic process?. End. Lecture 7.2 – Heating Curves and Phase Diagrams. Today ’ s Learning Targets.

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Catalyst

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  1. Catalyst • Define endothermic. Give an example. • Define exothermic. Give an example • I cool a glass of water, is this an endothermic process or an exothermic process? End

  2. Lecture 7.2 – Heating Curves and Phase Diagrams

  3. Today’s Learning Targets • 7.3 – I can draw a phase diagram to describe how pressure and temperature are related and discuss what a triple point is. • 7.4 – I can analyze and draw a heating curve to describe how energy is lost or gained while a substance changes phases. I can identify on the graph the Hfusion and the Hvaporization. • 7.5 – I can describe a reaction using the ideas of enthalpy and entropy.

  4. Today’s Focus Question • How much energy is required to turn my Flamin’ Hot Cheetos into a liquid?

  5. What are enthalpy and entropy?

  6. I. Enthalpy (ΔH) • Enthalpyis a measure of the total energy that a system has. • Amount of energy released or absorbed during a process/reaction. • Measured in kilojoules (kJ)

  7. II. Entropy (ΔS) • The universe tends towards disorder. • Entropyis the measurement of the randomness or disorder of a system. • More energy = more disorder • Measure in J/K

  8. How are enthalpy and phase changes related?

  9. I. ΔHfusion and ΔHvaporization • Large amount of energy that is required to change phases • ΔHfusion= Energy to change solid to a liquid. • ΔHvaporization= Energy to change liquid to a gas. • ΔHfreezing= Energy to change liquid to a solid • ΔHcondensation= Energy to change gas to a liquid

  10. II. Heating Curves • Heating curves are graphs of the relationship between temperature and time. • Allow us to identify important values

  11. ΔH of vaporization/condensation ΔH of fusion/freezing

  12. Summarize

  13. Justify – TPS • Why was the water able to boil at room temperature when we dropped the pressure?

  14. How are pressure temperature and phase related?

  15. I. Pressure and Temperature • The state of matter of a substance depends on both the temperature and pressure • A phase diagram is a graph temperature, pressure, and phase for a substance

  16. II. Important Points on a Phase Diagram • Triple Point – The temperature and pressure conditions at which the solid, liquid, and gas phases of a substance coexist • Critical Point – The temperature and pressure at which the gas and liquid state become identical and form one phase.

  17. Melting/Fusion Freezing Vaporization Condensation Sublimation Deposition

  18. Class Example • You have a solid at a pressure of 30 atm and -15 oC, if you decrease the pressure at constant temperature, what phases will the substance go through?

  19. Table Talk

  20. Stop and Jot • Atmospheric pressure on Mt. Everest is 0.29 atm. What is the boiling point of water there using the phase diagram below.

  21. Summarize

  22. Vocab Direct Instruction Assignment • With our group, let’s do some vocab definitions! • Make a power point defining each of these terms: • Enthalpy • Entropy • Δhfusion • Δhvaporization • ΔHfreezing • Make a powerpoint slide for each vocab word with a picture, title, and a definition! • Δhcondensation • Heating curves • phase diagram • Critical Point • Triple Point

  23. Collaborative - Let’s Heat Some Water! • With the table complete the heating curve lab activity. • Heat the ice until it reaches a rolling boil • Show Mr. Astor when you are done

  24. Independent Work Time Complete the phase diagram homework you picked up when you came in.

  25. Learning Log Assessment Rate yourself 1 – 4 on LTs 7.3, 7.4, and 7.5

  26. Exit Slip • What is entropy? • Draw a basic heating curve. Have temperature on the y-axis and heat added on the x-axis. Label solid, liquid, gas, boiling, and freezing. • What is the triple point on the graph below?

  27. Learning Log Assessment Rate yourself 1 – 4 on LTs 7.3, 7.4, and 7.5

  28. Closing Time • Homework 7.2 due Monday/Tuesday • Rough Draft Due Monday/Tuesday • Quiz on Cheetos lab Monday/Tuesday

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