Question

The bonds in the reactants of Figure 7-3 contained 372 kJ of chemical energy and the bonds in the products contained 350 kJ of chemical energy. What is the amount of energy change during the reaction (show your work for full credit)? Would this energy be absorbed or released? Explain how you know.

Answer 1

Answer: 22 kJ amount of energy is released in the following reaction.

Explanation: There are two types of reaction on the basis of amount of heat absorbed or released.

1. Endothermic reactions: These are the type of reactions in which reactants absorb heat to form the products. The energy of the reactants is less than the energy of the products.

2. Exothermic reactions: These are the type of reactions in which heat is released from the chemical reactions. The energy of the products is less than the reactants.

Sign convention for $\Delta H$: This value is negative for exothermic reactions and positive for endothermic reactions.

For the given chemical reaction,

Energy of the products is less than the energy of the reactants, Hence, this reaction will be a type of exothermic reaction and energy will be released during this chemical change.

Amount of energy released = (350 - 372) kJ = -22kJ

Negative sign symbolizes the energy is being released. So, 22 kJ amount of energy is released in the following reaction.