The equation qr = ΔH represents:
Correct answer: A. Heat changes at constant pressure.
- A. Heat changes at constant pressure.
- B. Enthalpy.
- C. Pressure changes at normal pressure.
- D. None of the above.
Explanation
The equation qr = ΔH represents heat changes at constant pressure, as ΔH refers to the change in enthalpy, which is the heat absorbed or released during a process at constant pressure. Option A correctly identifies this relationship. Option B is incorrect because it only mentions the general concept of enthalpy without specifying the condition of constant pressure. Option C is incorrect because it misinterprets the relationship as involving pressure changes. Option D is incorrect as it dismisses the correct interpretation provided in option A.
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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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