Energy Changes in Chemical Reactions (5)

Example of energy level diagram for an endothermic reaction

Bridge map shows how the energy level diagram is constructed

Energy change during breaking and formation of bonds (1)

During a chemical reaction, the chemical bonds in the reactants are broken, and new bonds are formed in the products

Energy change during breaking and formation of bonds (2)

In an exothermic reaction, heat energy released during formation of the bonds in products is greater than heat energy absorbed to break bonds in reactants

Energy change during breaking and formation of bonds (3)

In an endothermic reaction, heat energy absorbed to break the bonds in the reactants is greater than heat energy released during the formation of the bonds in the product

Type of reaction that occurs when the hands feel cold when the disinfectant liquid containing alcohol evaporates while satinizing the hands

Endothermic reaction

Type of reaction when the hands feel hot when the detergent powder on the hands is dipped in water

Exothermic reaction

Bond energy for bond H-H

436 kJ mol-1

Bond energy for bond Cl-Cl

243 kJ mol-1

Bond energy for bond H-Cl

432 kJ mol-1

Chemistry

Question

Energy Changes in Chemical Reactions (5)

Energy Changes in Chemical Reactions (5)