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Enthalpy Change Of Formation Formula:
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The enthalpy change of formation (ΔH_f) is the heat change when one mole of a compound is formed from its elements in their standard states. It is a fundamental thermodynamic property used to characterize chemical compounds.
The calculator uses the enthalpy change of formation formula:
Where:
Explanation: This formula calculates the enthalpy change per mole of substance formed during a chemical reaction.
Details: Enthalpy change of formation values are essential for predicting reaction energies, determining thermodynamic stability of compounds, and calculating overall energy changes in chemical processes.
Tips: Enter the total enthalpy change of the reaction in kJ and the number of moles of substance formed. Both values must be positive numbers.
Q1: What is the standard enthalpy of formation?
A: The standard enthalpy of formation (ΔH_f°) is the enthalpy change when one mole of a compound is formed from its elements in their standard states at 1 atm pressure and 298 K.
Q2: How is this different from reaction enthalpy?
A: Reaction enthalpy is the total energy change for a complete reaction, while formation enthalpy is specific to the formation of one mole of a particular compound.
Q3: Can this be used for any chemical reaction?
A: This calculation applies specifically to reactions where the compound of interest is being formed from its constituent elements.
Q4: What are typical values for enthalpy of formation?
A: Values vary widely depending on the compound. Stable compounds typically have negative ΔH_f values, indicating exothermic formation.
Q5: How accurate is this calculation?
A: The accuracy depends on the precision of the input values. For standard values, consult thermodynamic reference tables.