A wastewater treatment facility undergoes a process to aerate water in order to dissolve oxygen gas. Focusing on one treatment tank with a liquid volume of 4.7 m³, it has a bulk concentration of 7.1 mol L^-1 and the concentration of oxygen at the gas-liquid boundary is 2.1 mol L^-1. What is the total rate of interphase transfer (umol s^-1) given the mass-transfer coefficient is 18.8 x 10^-3 cm s^-1 and the area available for interphase mass transfer is 2.0 m²?