Question

4. Describe in detail the relationship between chemical bonds and energy. What must be true of the bonds for a reaction to be endothermic, and what must be true for the reaction to be exothermic?

Answer 1

Analysis and Conclusion:

1. What chemical combination did you investigate?

My answer: Vinegar and baking soda.

2. Did the observed temperature of the solution increase or decrease?

My answer: Decrease

3. Based on your observation, was the reaction endothermic or exothermic? Explain your answer using complete sentences.

My answer: The reaction was endothermic, because there was an decrease in temperature.

4. Describe in detail the relationship between chemical bonds and energy. What must be true of the bonds for a reaction to be endothermic and what must be true for the reaction to be exothermic?

My answer: When bond is formed, energy is released, and it must be supplied when the bond is broken. Basically breaking and making of bonds requires energy.

Endothermic reaction: As in the text, Energy needed to break the bonds in the reactants is greater than the energy released as bonds in the products are formed.

Exothermic Reaction: As in the text, Energy needed to break the bonds in the reactants is less than the energy released as bonds in the products are formed. If the total energy needed to break all of the bonds in the reactants is less than the total energy released when all of the new bonds in the products are formed, the reaction is exothermic.

Answer 2

When a bond is formed, the energy is released. Also, it must be supplied when the bond is broken.
In an endothermic reaction, the energy required to break the bond in the reactants must be greater than the energy released forming the bond in the product.
In an exothermic reaction more energy is released in forming the bonds on the product than is absorbed to break the bonds in the reactants.