Explain the difference between endothermic and exothermic chemical reactions
Endothermic and exothermic chemical reactions describe the flow of energy during a chemical reaction.
1. Endothermic reactions:
Endothermic reactions are chemical reactions that absorb energy from the surroundings in the form of heat. In these reactions, the products have higher energy compared to the reactants, as energy is absorbed from the environment. This results in the transfer of thermal energy from the surroundings into the system. Endothermic reactions occur when the bonds in the reactants are broken, and new bonds are formed to create the products. Examples of endothermic reactions are photosynthesis, evaporation, and the reaction between citric acid and baking soda in a cold pack.
2. Exothermic reactions:
Exothermic reactions are chemical reactions that release energy to the surroundings in the form of heat. In these reactions, the products have lower energy compared to the reactants, as energy is released during the reaction. This causes the system to lose thermal energy, transferring it to the surroundings. Exothermic reactions occur when the bonds in the reactants are formed, releasing energy. Examples of exothermic reactions are combustion reactions like burning wood or fuel, the reaction between baking soda and vinegar, and the reaction between hydrochloric acid and sodium hydroxide.
In summary, endothermic reactions absorb energy from the surroundings, resulting in an increase in the energy of the products. Exothermic reactions release energy to the surroundings, leading to a decrease in energy for the products.