What does one mean by exothermic and endothermic reactions? Give examples.

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Ques 9: What does one mean by exothermic and endothermic reactions? Give examples.  

Ans 9: 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. 

              2 Na + Cl2 →2 Na Cl

In other words, combination reactions are exothermic. 

Reactions that require energy or absorb   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.

      6 CO2 + 6 H2O → C6H12O6 + 6 O2



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