ENTHALPY OF FORMATION OF AQUEOUS HYDROFLUORIC ACID: REVISION NEEDED?

Area of Science:

• Thermochemistry
• Physical Chemistry
• Fluorine Chemistry

Background:

• Accurate enthalpies of formation for hydrofluoric acid (HF) are essential for interpreting combustion calorimetry data of fluorinated compounds.
• Existing recommendations for HF enthalpies exhibit inconsistencies with published experimental data, impacting derived values.
• Previous analyses have not fully incorporated all available experimental data, leading to potential inaccuracies.

Purpose of the Study:

• To provide updated and more consistent recommendations for the enthalpies of formation of hydrofluoric acid.
• To address inconsistencies in current literature values for HF enthalpies.
• To identify limitations in existing experimental data and suggest future research directions.

Main Methods:

• Comprehensive analysis of available experimental data on hydrofluoric acid formation enthalpies.
• Inclusion of previously overlooked experimental sources.
• Comparative analysis of current recommendations against experimental findings.

Main Results:

• Revised recommendations for hydrofluoric acid enthalpies of formation show improved consistency with experimental data.
• The study identified significant scatter in existing experimental data, limiting further precision.
• Discrepancies between recommended and experimental values were reduced but not eliminated.

Conclusions:

• The revised enthalpies of formation for hydrofluoric acid offer a more reliable basis for thermochemical calculations.
• Further experimental measurements, especially for aqueous HF solutions, are necessary to reduce uncertainty.
• Advancements in the thermochemistry of fluorinated compounds depend on improved fundamental data for HF.