Which reaction is exothermic?
A. Cellular respiration
B. Photosynthesis
C. Baking soda + vinegar
D. Melting Ice***
No, melting ice requires heat, the melting is endothermic.
To determine which reaction is exothermic, we need to understand what an exothermic reaction is. An exothermic reaction is a chemical reaction that releases energy in the form of heat. In other words, it is a reaction that produces heat as a byproduct.
Now, let's analyze each option and determine which one is exothermic.
A. Cellular respiration: Cellular respiration is a metabolic process occurring in cells that converts nutrients into energy. This energy is typically stored in the form of adenosine triphosphate (ATP). Although cellular respiration is an essential process in living organisms, it is not an exothermic reaction. Instead, it is considered an endothermic reaction because it requires energy input to occur.
B. Photosynthesis: Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy, usually in the form of glucose. Photosynthesis is also not an exothermic reaction; it is an endothermic reaction because it requires energy from light to proceed.
C. Baking soda + vinegar: When baking soda (sodium bicarbonate) and vinegar (acetic acid) are mixed together, they undergo a chemical reaction. This reaction produces carbon dioxide gas, water, and a compound called sodium acetate. The reaction between baking soda and vinegar is indeed exothermic. The release of gas and the resulting fizzing is an observable indicator of energy being released in the form of heat.
D. Melting Ice: The process of ice melting is a physical change rather than a chemical reaction. When ice melts, it absorbs heat energy from its surroundings, making it an endothermic process rather than exothermic.
Therefore, the correct answer is C. Baking soda + vinegar.