Bond Energy Unit 3

Front

What is bond energy?

Back

Bond energy is the amount of energy required to break one mole of bonds in a substance, measured in kilojoules per mole (kJ/mol).

Front

What is an endothermic reaction?

Back

An endothermic reaction is a chemical reaction that absorbs energy from its surroundings, resulting in a net gain of energy in the system.

Front

What is an exothermic reaction?

Back

An exothermic reaction is a chemical reaction that releases energy to its surroundings, usually in the form of heat.

Front

What does +ΔH indicate in a reaction?

Back

+ΔH indicates that the reaction is endothermic, meaning it absorbs heat.

Front

What does -ΔH indicate in a reaction?

Back

-ΔH indicates that the reaction is exothermic, meaning it releases heat.

Front

How can you determine if a reaction is exothermic or endothermic based on bond energies?

Back

If the total energy released in forming products is greater than the energy absorbed in breaking reactants, the reaction is exothermic. If the opposite is true, it is endothermic.

Front

What is the significance of bond formation in exothermic reactions?

Back

In exothermic reactions, more energy is released during bond formation in the products than is consumed in breaking bonds in the reactants.

Front

What is the significance of bond breaking in endothermic reactions?

Back

In endothermic reactions, more energy is absorbed to break bonds in the reactants than is released during bond formation in the products.

Front

What is the relationship between bond strength and bond energy?

Back

Bond strength is directly related to bond energy; stronger bonds have higher bond energies.

Front

What is the role of heat in chemical reactions?

Back

Heat can be absorbed or released during chemical reactions, influencing whether the reaction is classified as endothermic or exothermic.