1. A column of 0.094 m^2 cross section and 1.83 m high is packed with spherical particles of diameter 2 mm. When a pressure difference of 1090 kPa is maintained across the bed, a 60 per cent aqueous sucrose solution at 20C flows through the bed at a rate of 110.7 kg/min. At this temperature, the viscosity of the solution is = 0.57 Pas and its density is = 1286 kg/m3. What is the void fraction of the bed?