A tube has a length of 0.022 m and a cross-sectional area of 3.6 x 10-4 m2. The tube is filled with a solution of sucrose in water. The diffusion constant of sucrose in water is 5.0 x 10-10m2/s. A difference in concentration of 3.9 x 10-3 kg/m3 is maintained between the ends of the tube. How much time is required for 7.0 x 10-13 kg of sucrose to be transported through the tube?