1. What does a negative enthalpy value indicate about a chemical reaction?
1. Heat is required for the reaction and is located on the left of the reaction.
2. Heat is required for the reaction and is located on the right of the reaction.
3. Heat is released and is located on the left of the reaction.
4. Heat is released and is located on the right of the reaction.
2. 67 K is equivalent to:
1.
2.
3.
4.
3.
is equivalent to:
1.
2.
3.
4.
4. Which of the following examples best represents heat?
1. A sample of platinum is
.
2. A piece of plastic contains 57 J of energy.
3. A piece of wood burns at
.
4. A toy car generates 45 J of kinetic energy.
5. Consider the combustion of propane
1. Is the combustion of propane endothermic or exothermic?
2. Is energy as heat released into the surroundings or absorbed by the system?
3. How much heat would this represent for the combustion of 3 moles of propane?
6. Calculate how much energy it takes to raise the temperature of 125 grams of aluminum from 100 to 245 degrees C. The specific heat of aluminum is 0.900 J/g degree C.
7. Calculate the heat change needed to raise the temperature of 1000 g of water from 5.0 degrees C to 95.0 degrees C.
8. How much energy is given off by the water in question number two if the 1000 g of water cools from 95.0 to 5.0 degrees C ?
9. Determine the specific heat of copper if it takes 10,500 J of energy to raise 520.0 grams of it from 27.0 degrees C to 245.0 degrees C
10. Determine the specific heat of an unknown element if it takes 540 J to raise the temperature of 55.6 grams of this element from 5.0 to 95.0 degrees C.
