Name ________________________________ Period ______
Chemistry I: Chapter 11 Worksheets
Worksheet #1
1. A student has 100ml of boiling water, 100ml of room temperature kool-aid and 100ml of iced tea. Explain the way that the temperature of each substance is related to the kinetic energy of its particles.
______________________________________________________________________________ ______________________________________________________________________________
2. Which of the following is true of chemical energy?
a. Chemical energy may be increased by adding heat.
b. In a solid, the atoms or molecules vibrate but do not move relative to each other because of chemical energy.
c. In a water molecule, the oxygen atom bonds to two hydrogen atoms because this minimizes the chemical energy.
d. Energy may be released as heat and light during a chemical reaction.
3. What are four examples of kinetic energy shown in the picture to the right? a. ___________________________________________
b. ___________________________________________ c. ___________________________________________ d. ___________________________________________
4. In question three, where would the skiers have had the highest potential energy?
___________________________________________________________
5. Write a letter “A” if the process below is endothermic, and a “B” if its exothermic. a. _____ water condenses on the outside of a glass
b. _____ sugar burns on the stove c. _____ a glowstick glows
Worksheet #2: Calculating Heat Changes with q = mCT
1. A 45 g piece of iron at 22°C was heated to 105 °C by adding 1678.5 joules of energy. What is the specific heat of the metal?
2. A 26.4 g sample of copper has a specific heat capacity of 0.3845 J/g°C. The copper is heated to 225°C and then cooled to 0°C. How much energy is released?
3. Answer the following questions.
a. When 80.0 grams of a certain metal at 90.0 °C was cooled to 30.0 °C, 619.22J of energy was released. What is the specific heat of the metal?
Extra Practice:
1. Temperature of a piece of Metal X with a mass of 95.4g increases from 25.0°C to 48.0°C as the metal absorbs 849 J of heat. What is the specific heat of Metal X?
2. When 435 J of heat is added to 3.4 g of olive oil at 21°C, the temperature increases to 85°C. What is the specific heat of the olive oil?
3. A piece of stainless steel with a mass of 1.55 g absorbs 141 J of heat when its temperature increases by 178°C. What is the specific heat of the stainless steel?
4. How much heat is required to raise the temperature of 250.0 g of mercury by 52°C?
6. How many kilojoules of heat are absorbed when 1.00 L of water is heated from 18°C to 85°C? (Hint: You first need to determine the mass of the water, then calculate q in the requested unit. The density of water is 1.00 g/mL)
7. A piece of aluminum with a mass of 100.0 g has a temperature of 20.0°C. It absorbs 1100 J of heat energy. What is the final temperature of the metal?
Worksheet #3: Calorimetry
Helpful information: Specific heat of water: 4.18 J/g°C
1. A 45 g piece of metal was heated to 105 °C and then dropped into a calorimeter containing 177 g of water. The temperature of the water in the calorimeter changed from 11 °C to 24.2 °C. What is the specific heat of the metal?
2. A 26.4g sample of copper is heated to 26.4°C and then placed in a calorimeter containing 34.9 g of water at 18.6°C. The final temperature of the metal and water is 33.7°C. Calculate the specific heat capacity of copper.
Worksheet #4: Heat Curve Practice
Helpful information:
Heat of vaporization of water: 2260 J/g Heat of fusion of water: 334 J/g
Specific heat of water: 4.18 J/g°C Specific heat of ice and steam: 2.06
J/g°C
1. How much energy (joules) must be absorbed by 20.0 g of water to increase its temperature from 283.0 °C to 303.0 °C?
2. Calculate how much energy (joules) is needed to change a 25.0 g sample of ice at 0.0 °C to liquid water at 32.8 °C.
3. How much energy (joules) is required to convert 21.6 g of water at 16.4 °C to steam at 121.2 °C?
4. How much energy (in calories) is needed to change 76 g of steam at 100.0 °C to liquid water at 12.8 °C?
5. Calculate the standard heat of formation for the following equations. ΔH°f values are given in
kJ/mol.
C6H12O6 (s) -1275.0 a. C6H12O6 (s) + 6 O2 (g) ---> 6 CO2 (g) + 6 H2O (l)
O2 (g) 0.00
CO2 (g) -393.5
H2O (l) -285.8 b. 4 NH3(g) + 7 O2(g) ---> 4 NO2(g) + 6H2O(g)
NH3(g) -45.90
NO2(g) +33.1
Chapter 11 Review
1. List two forms of kinetic energy and two forms of potential energy shown in this picture. a. Potential
i. _____________________________________________________ ii. _____________________________________________________ b. Kinetic
i. _____________________________________________________ ii. _____________________________________________________
2. How much energy must be added to 50.0 grams of water to raise its temperature from 40.0°C to 45.0°C.
3. How much energy must be added to 36.1g of ice at 0°C in order to raise its temperature to 25°C? 4. When a 255g of Al is cooled by 8.0°C, it is found to have lost 1794J of energy. What is the
specific heat of Al?
5. On the heating curve below, fill in the following terms. a. Condensation
b. Melting c. Freezing
d. Vaporization e. Solid
f. Liquid
g. Gas
h. Endothermic i. Exothermic
6. In a calorimeter, the temperature of 60.0g of water increases from 23.3°C to 38.7°C when a 102.4°C block of Ni is dropped in. If the mass of the block is 19.4g, what is the specific heat of the nickel?
7. Find the heat of formation of the following equations. a. Fe3O4(s) + CO(g) → 3FeO(s) + CO2(g)
b. 4Ag(s) + 2H2S(g) + O2(g) → 2Ag2S(s) + 2H2O(l)
8. It takes 679J of energy to raise the temperature of 132.6g of mercury from 20.0 oC to 68.9oC.
Calculate the specific heat of mercury.
9. A 45g piece of metal was heated to 45.9 oC and then placed in a calorimeter containing 100.0 g
of water at 18.6 oC. The final temperature of the mixture was 33.7 oC. Calculate the heat capacity
of the metal.
10. How much energy in joules is required to change 76g to steam at 100oC to ice at -10.0oC?
Substance ΔHf (kJ/mol)
Ag(s) 0.0
H2S(g) -20.6
O2(g) 0.0
Ag2S(s) -32.6
Solve the following crossword using unit vocabulary.
ACROSS
8. The sign of an enthalpy change that is exothermic. 9. The sign q has for an endothermic change.
11. The difference between heat capacity & specific heat capacity.
12. A played out 90's expression; also a type of calorimeter.
14. Energy is neither created nor destroyed, only transferred and transformed.
17. A substance that slows the transfer of heat. 18. Digestion of food is an ____________ process. 19. A unit of energy
20. A common compound that has a high specific heat.
DOWN
1. ΔH. Is equal to q when all the change in energy occurs as heat.
2. The study of the energy changes in chemical reactions.
3. An apparatus used in the determination of the heat of a reaction.
4. Symbolized as q.
5. Freezing ice is an example of this type of process. 6. The surroundings of an exothermic reaction will feel ____.
7. That part of the universe other than the system being studied.
10. Food energy is measured in this unit.
13. The heat content of a system (the total energy of a system).
