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Chemical Reactions and Equations — Science STD 10 — Question

CBSE BoardEnglish MediumSTD 10ScienceChemical Reactions and Equations3 Marks
Question
What does one mean by exothermic and endothermic reactions? Give examples.
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Answer

A reaction in which energy is released in the form of heat or light is called exothermic reaction. Example of exothermic reaction are:
  1. CH4 + 2O2 → CO2 + 2H2O + heat
  2. 2Al + FeO3 → Al2O3 + Fe + heat
A reaction in which energy is absorbed from the surrounding and cooling is produced is called endothermic reaction. Example of endothermic reaction are:
  1. CaCO3 → CaO + CO2
  2. N2 + O2 → 2NO

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