Exothermic and Endothermic Reactions

Question 1

Chemical Energy

Answer 1

-energy stored in the chemical bonds of a substance
-chemical reactions always involve energy changes
-making bonds and breaking bonds involve energy changes

Question 2

Activation Energy

Answer 2

the energy required to break the bonds in the reactants for a chemical reaction to occur

Question 3

How to identify if a reaction is exothermic?

Answer 3

If more energy is released than supplied

Question 4

How to identify if a reaction is endothermic

Answer 4

if more energy is supplied than is released

Question 5

Exothermic or Endothermic

Answer 5

based on the type of energy (heat) change involved, chemical reactions are classified as either Exothermic or Endothermic

Question 6

Exothermic

Answer 6

-energy is released
-heat (energy) given off
-temperature of the substance rises
-products feel hot

Question 7

Endothermic

Answer 7

-energy is absorbed
-heat (energy) taken in
-temperature of the substance drops
-products feel cold

Question 8

endothermic reactions

Answer 8

reactants + energy = products
reactants + heat = products

Question 9

endothermic formula

Answer 9

6CO2 + 6H2O + Energy - C6H12O6 + 6O2

Question 10

exothermic formula

Answer 10

CH4 + 2O2 - CO2 + 2H2O + Energy

Question 11

Example of exothermic

Answer 11

-combustion of fuels
-yeast & hydrogen peroxide
-Epson salts & water

Question 12

Example of endothermic

Answer 12

-photosynthesis
-acidic acid & sodium bicarbonate