1. Chapter 12 Temperature and Heat Temperature – Average kinetic energy of molecules. Heat – Transfer of energy due to temperature difference; flows from hot to cold.

2. 12.1 – Common Temp Scales

3. 12.2 – The Kelvin Temp Scale

4. 12.4 – Linear Thermal Expansion Most materials expand when heated and contract when cooled. The change in length (ΔL) depends on… 1. the material (α) 2. the original length (L 0 ) 3. the temperature change (ΔT) α = coefficient of linear expansion [1/C°]

6. Bimetallic Strip – 2 different metals bonded together. A coiled bimetallic strip can be used in a thermostat

7. Which material has a higher coefficient of linear expansion?

9. 12.5 – Volume Thermal Expansion V 0 = original volume [m 3 ] β = coefficient of volume expansion [1/C°] Liquids typically expand more than solids; for most solids, β = 3 α. TABLE 12.1 (p.351)

11. ASSIGN: Ch. 12 #2, 5, 10, 13, 17, 26, 28 p. 375

12. 12.6 – Heat & Internal Energy Heat (Q) – transfer of energy due to a temperature difference, naturally flows from hot to cold. Heat is measured in Joules Internal Energy (U) – sum of energy due to molecular motion in a substance. A substance can’t have heat but can have internal energy.

13. 12.7 – Specific Heat Capacity Specific Heat Capacity (c) – the heat needed to be supplied or removed to change the temperature of a substance. Table of values on page 359 Heat (J) mass (kg) Specific heat (J/(kg∙C°) Change in temp (°C)

14. When two objects transfer heat with no heat loss to the surroundings…

15. 12.7 – Latent Heat Latent Heat – the heat that must be supplied or removed to change the phase of a substance. L f – latent heat of fusion (solid liquid) L v – latent heat of vaporization (liquid gas) L s – latent heat of sublimation (solid gas) Heat (J) mass (kg) latent heat (J/kg) Table of values on page 364

16. 12.7 – Latent Heat L f – latent heat of fusion (solid liquid) = 33.5 x 10 4 J/kg = 80 cal/g L v – latent heat of vaporization (liquid gas) = 22.6 x 10 5 J/kg = 540 cal/g Table of values on page 364 For water….

17. 12.8 – Equilibrium Between Phases Equilibrium Vapor Pressure – the pressure of the vapor that coexists in equilibrium with the liquid. Boiling Point – the temperature where the vapor pressure of the liquid equals the atmospheric pressure.

18. 12.8 – Equilibrium Between Phases Water boils when its vapor pressure equals the atmospheric pressure.

19. ASSIGN: Ch. 12 #41, 44, 45, 51, 52, 62,