The amount of heat provided to a system at constant pressure (qp) is equal to _.
Correct answer: B. Change in enthalpy (ΔH)
- A. Change in internal energy (ΔE)
- B. Change in enthalpy (ΔH)
- C. Change in free energy (ΔG)
- D. Change ín temperature only (ΔT)
- E. Change in pressure only (ΔP)
Explanation
At constant pressure, the heat of reaction is equal to the enthalpy change of the system. Most chemical reactions occur at constant pressure, so enthalpy is more often used to measure heats of reaction than internal energy.
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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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