During a chemical reaction, heat of formation is
Correct answer: C. Either Evolved or Absorbed
- A. Evolved
- B. Absorbed
- C. Either Evolved or Absorbed
- D. None of the above
Explanation
The heat of formation, also known as the standard enthalpy of formation, is the heat change accompanying the formation of one mole of a substance from its elements in their standard states. This can be either an exothermic process (heat evolved) or an endothermic process (heat absorbed), depending on the specific reaction.
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About Enthalpy
Enthalpy is the heat content of a system measured at constant pressure, and its change indicates whether a reaction or physical process is endothermic or exothermic. The topic covers state functions, enthalpy diagrams, standard enthalpy of formation, combustion and neutralisation, and the relationship between ΔH and internal energy change.
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