Pressurometric titrations with xenon trioxide as oxidant

Area of Science:

• Inorganic Chemistry
• Analytical Chemistry
• Redox Titration

Background:

• Xenon trioxide (XeO3) is a powerful oxidizing agent.
• Understanding its reaction stoichiometry with reducing agents is crucial for quantitative analysis.
• Previous studies often relied on less precise methods for determining reaction ratios.

Purpose of the Study:

• To qualitatively screen thirteen reducing agents for reactions with XeO3.
• To quantitatively determine the reaction stoichiometry of Fe(II) and Ti(III) with XeO3 using direct titration.
• To investigate the precision and potential byproducts of these redox reactions.

Main Methods:

• Qualitative screening of thirteen reducing agents against XeO3.
• Direct titration of Fe(II) and Ti(III) with XeO3.
• Pressurometric end-point detection for precise titration measurements.

Main Results:

• The Fe(II)/XeO3 reaction ratio varied between 5.85 and 5.95.
• The Ti(III)/XeO3 reaction ratio was consistently 5.93 ± 0.03, deviating from the theoretical 6.00.
• Oxygen production was observed in both titrations; hydrogen peroxide was detected in the Ti(III) reaction.

Conclusions:

• Direct titration with pressurometric detection provides high precision (parts per thousand) for XeO3 reactions.
• The observed non-stoichiometric ratios for Fe(II) and Ti(III) suggest complex reaction mechanisms or side reactions.
• The findings necessitate a re-evaluation of standard stoichiometric assumptions for certain XeO3 redox reactions.