Abstract

The hydrolysis of a solid NaOH microparticle in humid nitrogen and the chemical reaction between the resulting NaOH solution microdroplet and SO₂ gas have been studied with the use of elastic and inelastic (Raman) light scattering. A single solid NaOH particle was levitated electrodynamically in a reaction chamber and exposed to water vapor. After hydrolysis/deliquescence, the resulting solution droplet was exposed to SO₂ gas. Raman spectra and elastic resonance spectra collected during the reactions indicate that low SO₂ concentrations in the gas phase yield NaHSO₃ while high SO₂ concentrations result in NaSO₃ as the product. These results indicate that the reversibility of the key reactions becomes important when the SO₂ concentration is low.

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