Chemistry 10 Dr. Scholefield Chapter 3 Worksheet – Part B Homework is not collected or graded, but should be worked on seriously every week. Energy and the First Law of Thermodynamics 1. Define energy, and give three examples of different forms of energy. 2. State the First Law of Thermodynamics and give an example of this law in action. 3. A candy bar provides 265 Calories (empty!) of energy. Convert this to kJ. 4. The combustion of a piece of wood releases 164.2 kJ of energy. Convert this to calories. Temperature Scales and Unit Conversions 5. Which temperature scale: -- is designed based on the freezing and boiling point of water? -- is referred to as the absolute temperature scale? 6. Liquid nitrogen has a temperature of 77 K. Convert this to ºC. 7. A person with a fever has a temperature of 101.8 ºF. Convert this to ºC. 8. Ethanol boils at a temperature of 78.6 ºC. Convert this to ºF and K 9. A recipe requires an oven temperature of 450 ºF. Convert this to K.Specific Heat Capacity and Temperature Changes 10. Consider a piece of granite and a piece of oak-wood, both with the same mass and at the same temperature. If the same amount of heat is added to each of them, which substance would end up at the lower temperature? The SHC of granite is 0.79 J/g•C and the SHC of oak-wood is 2.00 J/g•C. Explain your answer. 11. A 45.0 gram sample of lead at 26.0 C is placed in some boiling water at 100. C. How much heat is absorbed by the lead when its temperature equals that of the boiling water? The SHC of lead is 0.128 J/g•C. 12. A 1680 cg sample of nickel is cooled by removing 0.347 kJ of heat from it. If the initial temperature of the nickel is 35.2 C, what is its final temperature? The SHC of nickel is 0.444 J/g• C. 13. A bar of gold initially at 133.5 C is cooled by removing 5.4 kJ of heat. If its final temperature is 23.6 C, what is the mass of the gold bar, in grams? The SHC of gold is 0.128 J/g•C. 14. You heat a metal sample weighing 2.07 oz by adding 82.5 cal of heat energy to it. The temperature rises from 20.30 C to 26.83 C. What is the specific heat capacity of this metal, in J/g• C? 15. A cup of pistachio nuts has a caloric value of 78.7 Cal. If all the heat energy from these nuts was transferred to exactly 1 quart of water at 10.0 C, to what temperature will the water rise (in C)? The SHC of water is 4.184 J/g• C, and the density of water is 0.9997 g/mL. 16. A 125 g rock is heated to 93 C, and then dropped into 100. g of water at 19 C. Heat is transferred between the rock and water until thermal equilibrium is reached at 31 C. Calculate the specific heat capacity of the rock in J/g• C. Note that the heat gained by the water equals the heat lost by the
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