1. Warmup 25g of ice cubes at -10*C are added to 250g of water at 30*C. Predict based on past experience what the equilibrium temperature is. Then calculate the equilibrium temperature. How would you reconcile the difference between those two answers.

2. Latent Heat and Phase Change FEBRUARY 1, 2012

3. Temperature is related mostly to: 1.Average molecular kinetic energy in a substance. 2.Total kinetic energy in something. 3.Average energy in a substance. 4.Total energy in something. 5.Average kinetic energy of an object.

4. Which temperature scale labels the freezing point of water at 0 degrees? 1.Celsius 2.Caloric 3.Kelvin 4.Fahrenheit 5.None of the above

5. Heat is the: 1.Average amount of energy per molecule contained in an object. 2.Total amount of energy contained in an object. 3.Energy transferred between objects because of a temperature difference. 4.Amount of energy all molecules have. 5.None of the above.

6. If the specific heat of water were higher, lakes would be: 1.More likely to freeze. 2.Less likely to freeze. 3.More likely to have ice float. 4.More likely to evaporate. 5.Neither of the above.

7. Which of the following describes a transfer of energy? 1.Heat 2.Temperature 3.Kinetic Energy 4.Internal Energy 5.None of the above

8. You’re feeling sick and place a thermometer on your tongue. The instructions say to wait three minutes. This makes sense because: 1.It takes time for the thermometer to reach its activation energy. 2.It takes time to reach thermal equilibrium. 3.It takes time to raise your body’s interal temperature. 4.It takes time to attain a state of contact. 5.None of the above.

9. Which of the following best describes the relationship between two systems in thermal equilibrium? 1.No net energy is exchanged. 2.The volumes are equal. 3.The masses are equal. 4.The velocity is zero. 5.The molecular speeds are equal.

10. Solid LiquidGasPlasma Less EnergyMore Energy ColderHotter Melting Evaporating Ionizing Boiling Vaporizing Sublimating FreezingCondensing De-Ionizing Fusion Phase Changes

11. Latent Heat and Phase Change In solids…In liquids Latent heat is the energy required to break connections between molecules in order to cause a phase change. Energy used for latent heating does not affect the molecular kinetic energy, and therefore does not affect temperature.

12. Full Explanation 1) Energy conversion of flame 2) Heat flow 3) Temperature increase OR Latent Heat 4a) Energy causes change in bonds 4b) Hottest escape, cooler stay behind 5) Plateaus in graph

13. Substance Latent Heat Fusion kJ/kg Melting Point °C Latent Heat Vaporization kJ/kg Boiling Point °C Alcohol, ethyl108−11485578.3 Ammonia339−751369−33.34 Carbon dioxide184−78574−57 Helium 21−268.93 HydrogenHydrogen(2)58−259455−253 Lead [8] 24.5327.58711750 Nitrogen25.7−210200−196 Oxygen13.9−219213−183 R134a −101215.9−26.6 Toluene −93351110.6 Turpentine 293 Water33402260100 Latent Heat Values