(Photo credit: mandy&john)
Endothermic and Exothermic Reactions & Processes are commonly observed in our everyday life.
These energy changes are either occurring naturally (combustion/burning, photosynthesis, respiration, boiling, freezing, etc) or being employed by mankind to make our lives better through its numerous application.
One of the most common application is the use of Cold Packs in our daily lives.
When you have a headache, applying a cold pack relieve the pain. Most of the commercially available cold packs contain chemicals which take in heat when they react. This is why cold packs causes a cooling effect on their person’s head and temporarily relieve the pain.
Chemistry Concepts behind the Use of Cold Packs:
What really happens is that when the cold pack is used, the chemicals inside the pack are made to react with each other and this reaction (i call this the SYSTEM) is highly Endothermic in nature – heat energy is taken into the SYSTEM from the SURROUNDING. The SURROUNDING in this case is the person’s head.
The cold pack can simply be made up of 2 bags – a small inner bag and an outer bag. The small inner bag can be just water and the out bag can be ionic salts such as Ammonium Chloride or Potassium Nitrate. When the pack is squeezed, the small inner bag breaks and the ionic salt dissolves in water. This causes a reaction which is Endothermic in nature.
How about an alternative to Cold Pack?
Now, i have never use a Cold Pack when i am young because my family was poor. When we have an headache or a fever, and need to cool down the temperature & pain – my parents would instead wrap some ice inside a small towel and hold it against my forehead. The concepts is the same as the cold pack.
As the ice melts to become liquid water, it would take in energy from the surroundings and MELTING is considered a ENDOTHERMIC Process. In this case, the solid ice becomes the SYSTEM and our forehead becomes the SURROUNDING. The SYSTEM takes in heat energy from the SURROUNDING – directly removing heat from our forehead and thus the pain.
PS: How do you find this post on Everyday Life Examples of Chemistry? I would love to hear from you.
Your explanations in the the application of the endothemic reaction in the works of life was simply what I needed to complete my assignment and it is simple to understand too.
thanks that will help me in my homework
i am happy to note those excellent results for my search thanku……… 🙂
Thank you for the compliments.
I am glad that you find the blog posts useful to you.
Feel free to share it with your friends that need help in Chemistry.
Keep Sharing, Keep Learning,
Sean 🙂
Thanks, Sean. It has helped me in completing my homework and understanding these reactions. At the same time, it is very well explained.
It’s more useful for student’s like us.It will be more useful if more information are also included.