A bauble column (BC) is a gas - liquid contactor used to achieve mass transfer between liquid & gas. It has a wide range of applications in chemical & process engineering. The gas hold- Up (Eg) & the volumetric liquid phase mass transfer coefficient (KLa) were studied experimentally in the present work by using ethanol - water mixture as liquid phase & air as a gas phase. The study was developed to express the effects of the process variables on Eg & KLg the exponential work was designed for this purpose in the following experimental range: 1.Weight percent of ethanol in water (0- 0.8) Wt%. 2.Superficial gas velocity of air (0.01-0.11) m/s. 3.Operation temperature (26-27) °C. 4.Operating pressure (1× 105 - 6×105) N/m2