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Enthalpy Change Equation:
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Enthalpy change of neutralisation (ΔH) is the heat energy change when one mole of water is formed from the reaction between an acid and a base under standard conditions. It is typically an exothermic process, indicated by a negative ΔH value.
The calculator uses the enthalpy change equation:
Where:
Explanation: The negative sign indicates that the reaction is exothermic (releases heat). The equation calculates the enthalpy change per mole of water formed.
Details: Calculating enthalpy change of neutralisation helps determine the energy changes in acid-base reactions, which is fundamental in thermodynamics and has applications in industrial processes, environmental science, and chemical engineering.
Tips: Enter the heat energy released (q) in kJ and the moles of water produced (n) in mol. Both values must be positive, with n > 0.
Q1: Why is the enthalpy change negative?
A: The negative sign indicates that the reaction is exothermic, meaning heat is released to the surroundings during neutralisation.
Q2: How do I measure heat energy (q)?
A: Heat energy is typically measured using calorimetry: q = m × c × ΔT, where m is mass, c is specific heat capacity, and ΔT is temperature change.
Q3: What are typical values for enthalpy change of neutralisation?
A: For strong acids and strong bases, ΔH is approximately -57 kJ/mol. Values may vary for weak acids or bases due to incomplete dissociation.
Q4: Does concentration affect enthalpy change?
A: For ideal solutions, enthalpy change should be concentration-independent, but real solutions may show variations due to non-ideal behavior.
Q5: Can this calculator be used for any acid-base reaction?
A: Yes, but ensure accurate measurement of moles of water produced and heat energy released for correct results.