AbstractFree convective effects on forced convective mass transfer in the Stokes flow region were studied experimentally by using a single drop in a liquid‐liquid system.Liquids used to form the drops were methyl acetate or 2‐ethoxyethyl acetate with distilled water as the continuous medium. Spherical drops were formed on the capillary tip of a 0.58 cm. O.D. capillary glass tube centered in a 2.5 cm. O.D. pyrex tubular flow cell.Results are presented graphically as NSh vs. NPe, NSh vs. NRe, and NSh/NRa1/4 vs. NPe to show the variation of mass transfer with flow rate and free convection. The range of variables was 10 ≤ NPe ≤35,000; 0.1 ≤ NRe ≤ 30; 578 ≤ NSc ≤ 1,149; and 12.3 ≤ NGr ≤ 75.7.Satisfactory comparisons were also made with other investigators' findings.Results substantiate that at low flow rates (Reynolds number < 10, Peclet number < 1,000) free convective effects either reinforce or interfere with mass transfer. This interference takes place until flow becomes high enough to overcome interfering effects of free convection.