Endothermic and Exothermic Reactions

Front

What is an exothermic reaction?

Back

A reaction that releases energy, usually in the form of heat, to its surroundings.

Front

What is an endothermic reaction?

Back

A reaction that absorbs energy from its surroundings, usually in the form of heat.

Front

What is activation energy?

Back

The minimum amount of energy required to start a chemical reaction.

Front

What does the law of conservation of energy state?

Back

Energy cannot be created or destroyed, only transferred and transformed.

Front

What happens to energy in an exothermic reaction?

Back

More energy is released when the bonds in the products are formed than is used to break the bonds in the reactants.

Front

What happens to energy in an endothermic reaction?

Back

It takes more energy to break the bonds of the reactants than is released when the bonds in the products are formed.

Front

Give an example of an exothermic reaction.

Back

Combustion of fuels, such as burning wood or gasoline.

Front

Give an example of an endothermic reaction.

Back

Photosynthesis, where plants absorb sunlight to convert carbon dioxide and water into glucose.

Front

What is a hand warmer an example of?

Back

An exothermic reaction, as it releases heat to warm the hands.

Front

What is the role of catalysts in chemical reactions?

Back

Catalysts lower the activation energy required for a reaction to occur, speeding up the reaction without being consumed.