Name:
Endothermic and Exothermic Reactions
Read the following scenarios and determine if the reaction is Endothermic or Exothermic? Explain which is the
system and which is the surroundings.
1. Your car burns gasoline as you drive from home to school
2. Jerry is baking homemade bread in the oven.
3. The ice melts in your glass of water.
4. Sodium and chlorine combine in an explosive reaction to form table salt.
5. Barry lights his candles to get his hot air balloon to fly.
6. Water freezes on the pavement and the roads become icy.
7. Mom puts a pot of water on the stove and the water begins to boil.
8. Water condenses on the side of your glass of cold lemonade.
9. A glass of water left out overnight evaporates.
10. A plant carries out photosynthesis.
11. A tree grows.
12. The snow melted when we finally had a warm day last week.
13. Corey adds hydrochloric acid slowly to water and notices that the flask feels hot.
14. The trainer shakes a cold pack to put it on an injured student’s knee.
15. An egg is cooked in a frying pan.
Thermochemistry
1. Based upon the thermochemical equation given, calculate the heat absorbed with the formation of 1.15 g of
NO2(g).
N2(g) + 2 O2(g)  2 NO2(g)
∆H = +67.6 kJ
2. What quantity of heat is associated with the synthesis of 45.0 g of NH3, according to the following
equation?
4 NO(g) + 6 H2O(l)  4 NH3(g) + 5 O2(g)
∆H = +1170 kJ
3. Given the following equation:
CH4(g) + 2 O2(g)  CO2(g) + 2 H2O(l)
∆H = -890.4 kJ
a. How much energy is given off when 5.00 moles of CH4 are burned?
b. How much energy is released when 85.6 grams of CH4 are burned?
c. If you were to attempt to make 60.0 g of methane (CH4) from CO2 and H2O, how much energy would be
needed?
4. Use the following synthesis reaction to answer the following questions:
N2(g) + 2 O2(g)  2 NO2(g) H = – 296.9 kJ
a. If we change equation by reversing the reaction, what would happen to the H?
b. If we double the number of moles in the equation, what would happen to the H?
5. Use the following decomposition reaction to answer the following questions:
2H2O(g) + heat  2H2(g) + O2(g)
a. Is this reaction Endothermic or Exothermic and how do you know?
b. When I decomposed water the temperature rose from 19°C to 26°C. True or false, this is an
endothermic reaction. Explain.
Name:
Endothermic and Exothermic Reactions
Read the following scenarios and determine if the reaction is Endothermic or Exothermic? Explain which is the
system and which is the surroundings.
1. Your car burns gasoline as you drive from home to school
2. Jerry is baking homemade bread in the oven.
3. The ice melts in your glass of water.
4. Sodium and chlorine combine in an explosive reaction to form table salt.
5. Barry lights his candles to get his hot air balloon to fly.
6. Water freezes on the pavement and the roads become icy.
7. Mom puts a pot of water on the stove and the water begins to boil.
8. Water condenses on the side of your glass of cold lemonade.
9. A glass of water left out overnight evaporates.
10. A plant carries out photosynthesis.
11. A tree grows.
12. The snow melted when we finally had a warm day last week.
13. Corey adds hydrochloric acid slowly to water and notices that the flask feels hot.
14. The trainer shakes a cold pack to put it on an injured student’s knee.
15. An egg is cooked in a frying pan.
Thermochemistry
1. Based upon the thermochemical equation given, calculate the heat absorbed with the formation of 1.15 g of
NO2(g).
N2(g) + 2 O2(g)  2 NO2(g)
∆H = +67.6 kJ
2. What quantity of heat is associated with the synthesis of 45.0 g of NH3, according to the following
equation?
4 NO(g) + 6 H2O(l)  4 NH3(g) + 5 O2(g)
∆H = +1170 kJ
3. Given the following equation:
CH4(g) + 2 O2(g)  CO2(g) + 2 H2O(l)
∆H = -890.4 kJ
a. How much energy is given off when 5.00 moles of CH4 are burned?
b. How much energy is released when 85.6 grams of CH4 are burned?
c. If you were to attempt to make 60.0 g of methane (CH4) from CO2 and H2O, how much energy would be
needed?
4. Use the following synthesis reaction to answer the following questions:
N2(g) + 2 O2(g)  2 NO2(g) H = – 296.9 kJ
a. If we change equation by reversing the reaction, what would happen to the H?
b. If we double the number of moles in the equation, what would happen to the H?
5. Use the following decomposition reaction to answer the following questions:
2H2O(g) + heat  2H2(g) + O2(g)
a. Is this reaction Endothermic or Exothermic and how do you know?
b. When I decomposed water the temperature rose from 19°C to 26°C. True or false, this is an
endothermic reaction. Explain.