Chemistry Chapter: Exothermic and Endothermic Reactions

Exothermic Reactions

• Exothermic reactions release heat energy, increasing the temperature of the surroundings
• Examples include combustion reactions, such as burning fuel, which release energy and heat up the surroundings
• The heat energy released can be used to cook food, warm up people, and increase the kinetic energy of air particles in the surroundings

Endothermic Reactions

• Endothermic reactions take in heat energy, decreasing the temperature of the surroundings
• Examples include treating sports injuries, where an endothermic reaction can be used to cool down the injured area and reduce pain
• Endothermic reactions are useful for cooling down injuries, promoting healing, and reducing pain

Determining Reaction Type

• To determine if a reaction is endothermic or exothermic, measure the temperature change of the surroundings
• Use a polystyrene cup, which is a good insulator, to minimize heat conduction
• Measure the starting temperature, add reactants, and monitor the temperature change
• If the temperature increases, the reaction is exothermic; if it decreases, the reaction is endothermic

Experimental Procedure

• Add one reactant to a polystyrene cup and measure the starting temperature
• Add the second reactant and stir to initiate the chemical reaction
• Monitor the temperature change to determine if the reaction is endothermic or exothermic

Exothermic Reactions

• Release heat energy, increasing the temperature of the surroundings
• Examples include combustion reactions, such as burning fuel
• Heat energy released can be used to cook food, warm up people, and increase kinetic energy of air particles

Endothermic Reactions

• Take in heat energy, decreasing the temperature of the surroundings
• Examples include treating sports injuries to cool down the injured area and reduce pain
• Useful for cooling down injuries, promoting healing, and reducing pain

Determining Reaction Type

• Measure temperature change of the surroundings to determine if a reaction is endothermic or exothermic
• Use a polystyrene cup to minimize heat conduction
• Measure starting temperature, add reactants, and monitor temperature change
• If temperature increases, the reaction is exothermic; if it decreases, the reaction is endothermic

Experimental Procedure

• Add one reactant to a polystyrene cup and measure the starting temperature
• Add the second reactant and stir to initiate the chemical reaction
• Monitor temperature change to determine if the reaction is endothermic or exothermic