Classify whether the reaction is exothermic or endothermic 1. Burning of wood 2. Exploding Firecrackers 3. Burning sulfur powder 4. Burning magnesium ribbon 5. Baking soda 6. A candle flame 7. Rusting iron 8. Cooking an egg 9. Separating ion pairs 10. Melting
The Correct Answer and Explanation is:
Here is the classification of the reactions as either exothermic or endothermic:
- Burning of wood – Exothermic
- Exploding firecrackers – Exothermic
- Burning sulfur powder – Exothermic
- Burning magnesium ribbon – Exothermic
- Baking soda – Endothermic (when heated, it undergoes decomposition)
- A candle flame – Exothermic
- Rusting iron – Exothermic
- Cooking an egg – Endothermic
- Separating ion pairs – Endothermic
- Melting – Endothermic
Explanation
Chemical reactions and physical changes can be classified based on whether they absorb or release energy. Exothermic reactions release heat energy to the surroundings, making the surrounding environment warmer. In contrast, endothermic reactions absorb heat energy, which cools the surroundings or requires continuous heating to proceed.
Combustion reactions such as the burning of wood, sulfur powder, and magnesium ribbon, as well as candle flames and exploding firecrackers, are all exothermic. These processes release a significant amount of heat and often light. The energy released comes from the chemical bonds in the reactants being converted into more stable products like carbon dioxide and water. Firecracker explosions also include rapid oxidation reactions that release stored chemical energy in the form of heat, sound, and light.
Rusting of iron, while slower and less dramatic, is also exothermic. This process releases a small amount of energy as iron reacts with oxygen and moisture to form iron oxide.
On the other hand, cooking an egg is an endothermic process. Heat is absorbed to break the bonds in the egg’s proteins, allowing them to unfold and recombine into a solid structure. Baking soda undergoes thermal decomposition when heated, absorbing heat to break down into sodium carbonate, water, and carbon dioxide, making it endothermic. Separating ion pairs and melting both require energy to overcome intermolecular or ionic forces, so they are classified as endothermic processes.
Understanding these classifications helps in various fields like chemistry, cooking, engineering, and even meteorology, as energy transfer plays a crucial role in both chemical and physical phenomena.
