Experiments on gas–liquid nucleation of sulfuric acid and water

We present measurements of binary homogeneous nucleation of sulfuric acid and water vapors at 298 K at two different relative humidities (38.2% and 52.3%), ${\mathrm{H}}_{\mathrm{2}}{\mathrm{SO}}_{\mathrm{4}}$ vapor concentrations ranging from about ${\text{1⋅10}}^{10}$ to ${\text{3⋅10}}^{10}$ molecules/cc. The experimental setup consisted of a turbulent mixing unit combined with a flow chamber where the nucleation took place. Particular attention was paid to the generation of sulfuric acid vapor. The measured nucleation rates vary between about 2 and $\text{3000\hspace{0.17em}}{\mathrm{cm}}^{\mathrm{-3}}{\mathrm{\hspace{0.17em}s}}^{\mathrm{-1}}.$ The results are compared with other measurements found in the literature. Our experimental rates are in agreement with predictions of the revised classical nucleation theory incorporating the hydration effect.