and r p for each kinetic data were experimentally determined by this work. For the case of the range of 10 -3 Pa s to 10 -1 Pa s, which still belongs to liquid phase (≪ 10 2 Pa s) and thus justifies the above assumption of a valid Stokes-Einstein relationship. The literature value of the bimolecular bulk reaction rate coefficient for the O 3 + S 2 O 2- 3 reaction (k BR ) is 3.7 × 10 8 M -1 s -1 at zero ionic strength. Under the condition where the droplet ionic strength, I, is not zero, the value of k BR (I) was calculated via empirical relationship of k BR and I, see the Supporting Information. It should note that the typical limit of diffusioncontrolled reaction rates, 1.4 × 10 11 M -1 s -1 , 53 is assumed as the upper limit of k BR at high ionic strengths (> 10 M). The partitioning coefficient of ozone (K sol,O3 ) was calculated via following empirical relationship of gas solubilities in salt solutions: 54