ENDOTHERMIC AND EXOTHERMIC

REACTIONS

EXOTHERMIC REACTIONS

• Chemical Reactions that RELEASE heat with the products.

You may see an exothermic reaction written like this…

REACTANTS PRODUCTS + ENERGY

OR

REACTANTS PRODUCTS + HEAT

ENDOTHERMIC REACTIONS

• CHEMICAL REACTIONS THAT ABSORB ENERGY OR HEAT IN THE REACTANTS.

You may see an endothermic reaction written like this…

ENERGY + REACTANTS PRODUCTSOR

HEAT + REACTANTS PRODUCTS

EVIDENCE OF REACTIONS

• AFTER AN EXOTHERMIC REACTION, THE PRODUCTS FEEL HOT!

• AFTER AN ENDOTHERMIC REACTION, THE PRODUCTS FEEL COLD!

ENDOTHERMIC OR EXOTHERMIC?

Sunlight + 6CO2 + 6H2O C6H12O6 + 6O2

CH4 + 2O2 CO2 + 2H2O + Energy

ENDOTHERMIC!

EXOTHERMIC!