When a solid melts there is:
Correct answer: A. Increase in enthalpy
- A. Increase in enthalpy
- B. Decrease in enthalpy
- C. No change in enthalpy
- D. Decrease in internal energy
Explanation
When a solid melts and transforms into a liquid, it requires an input of energy to break the intermolecular forces and allow the particles to move more freely. This energy input leads to an increase in the enthalpy of the system. The process is endothermic because heat is absorbed during the melting. Hence, the correct option is A) Increase in enthalpy.
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About Thermochemistry and Energetics of Chemical Reactions
Thermochemistry measures energy changes in chemical reactions and distinguishes exothermic from endothermic processes. Work covers systems, surroundings and state functions, internal energy, the first law of thermodynamics, enthalpy and Hess's law, including the sign conventions used when heat enters or leaves a system.
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