Which statement below correctly describes the energy changes during a chemical reaction? Explain.
a
Energy is released when bonds are broken, energy is also released when new bonds are formed.
b
Energy is absorbed when bonds are broken, energy is released when new bonds are formed.
c
Energy is absorbed when bonds are broken, energy is also absorbed when new bonds are formed.
d
Energy is released when bonds are broken, energy is absorbed when new bonds are formed.
The correct statement is option d: Energy is released when bonds are broken, and energy is absorbed when new bonds are formed.
During a chemical reaction, chemical bonds are broken in the reactant molecules to form new bonds in the product molecules. Breaking bonds requires energy input or absorption, as it involves overcoming the attractive forces holding the atoms together. This process is called an endothermic reaction.
On the other hand, when new bonds are formed, energy is released or given off to the surroundings. This energy release occurs as the atoms form more stable arrangements in the product molecules. This process is called an exothermic reaction.
In most chemical reactions, both bond breaking and bond formation occur simultaneously. Therefore, some energy is absorbed to break the existing bonds, and then energy is released when new bonds are formed. This overall energy change can be either endothermic or exothermic, depending on the net energy difference between the energy absorbed and released.