Week 19 1. A material that heats up and cools down quickly Is useful for storing heat energy. Has a high specific heat Is most likely water Has a low heat capacity. 2. How does a phase diagram indicate when a substance is changing phase? The temperature rises during a phase change The temperature is constant during a phase change The temperature falls during a phase change The temperature changes 20 C during a phase change

4. In solids, heat transfer occurs by 3. You feel warm when you stand under a heat lamp because energy moves to you by Conduction. C. Currents. Convection. D. Radiation. 4. In solids, heat transfer occurs by Convection Conduction Radiation Insulation

5. When the temperature of a particle rises, there is an increase in the Size c. Kinetic energy Potential energy d. Mass 6. How much heat is needed to raise the temperature of 2 kg of copper from 20 ͦC to 30 ͦC? (Specific heat of copper is 390 J/kg ͦC) 15,600 J c. 7,800 J 23,400 J d. 1,950 J

7. A 3kg iron sample requires a 1⁰C change in temperature to gain 390J of heat. What is its specific heat capacity? 1170 J C. 130 J 1170 J/kg ⁰C D. 130 J/kg ⁰C 8. What is the boiling point for the substance in the phase diagram shown below? 30 ͦC 140 ͦC 100 ͦC 70 ͦC

9. The specific heat of pure water is 4. 184 J/g C. A 10 9. The specific heat of pure water is 4.184 J/g C. A 10.00 g sample of pure water goes from 22.0-32.0 C. How much heat did the sample gain? 41.84 J c. 920.5 J 418.4 J d. 1339 J 10. Use the diagram to answer the question. What is the approximate temperature when this substance melts or freezes? 0 C 50 C -10 C 100 C