Question: What does one mean by exothermic and endothermic reactions? Give examples
Answer: Chemical reactions that release energy in the form of heat, light, or sound are called exothermic reactions.
Example: Mixture of sodium and chlorine to yield table salt
Na(s) + 1/2Cl₂(s) ⟶ NaCl(s) + 411KJ of energy
In other words, combination reactions are exothermic.
Reactions that absorb energy or require energy in order to proceed are called endothermic reactions.
For example: In the process of photosynthesis, plants use the energy from the sun to convert carbon dioxide and water to glucose and oxygen.
6CO₂(g) + 6H₂O(l) + Sunlight⟶ C₆H₁₂O₆(aq) + 6O₂(g)
