A liquid droplet of a substance (MA- 88 g/ mol) is suspended at the end of a very thin wire in a room containing a stagnant environment at 25.9C. Initial radius of the droplet r=3 mm, at 25.9C the substance vapor pressure is 4.38 kPa. The diffusion coefficient of the substance in the air is 0.090 cm/ s and its density is 0.6 kg/ m. Find the time (in minutes) it takes for the substance to evaporate completely