Lesson: Bond Energy Chemistry • First Year of Secondary School

Students will be able to

• define bond energy and state the units such values are given in,
• identify that the standard value of a bond strength is given per mole of bonds and not per bond,
• calculate the enthalpy of a reaction from given bond energies or vice versa,
• identify the relationship between bond energy and bond strength and the general trend in energies of single, double, and triple bonds,
• understand that bond making is exothermic and bond breaking is endothermic,
• understand that the overall heat change in a reaction depends upon the heat released from bond making versus the heat required for bond breaking,
• realize that many chemical reactions generally involve the breaking of chemical bonds, but the amount of energy needed can vary,
• identify the points at which bonds are broken and made on a reaction profile diagram.